Current Distribution and other antenna parameters of a half-wavelength Bowtie antenna operating at 750 MHz are analyzed using the Method of Moments (MoM) with the help of Rao-Wilton-Glisson (RWG) basis functions. The results are validated by comparing them with existing literature and other softwares. The efficiency and accuracy of the method are established through a series of studies.

The work presented in this paper proposes two passive antenna array designs for Side Looking Airborne Radar application toward maritime pollution surveillance. The first proposed design is a slotted waveguide passive array for the SLAR operation, having a cladded radome that meets the requisites at the simulation level, and has been validated with measurements. Second is an aperture coupled microstrip antenna array design which offers better control over the design parameters for achieving the intended performance. Both designs have lower weight compared to the other SLAR arrays while achieving narrow beam in azimuth, and 100 MHz bandwidth in X-Band.

In this paper we propose the use of light weight radars mounted on drones to carryout Radar Cross Section measurements in real environments and experimentally demonstrate its feasibility. Here we demonstrate the mono-static RCS measurement using light weight radar set-up mounted on Hexa-copter Drone. The measurements are done at 9GHz for demonstration and targets used are electric pole and corner reflector. The results are tabulated proving the feasible use of a light weight radars coupled with drones for RCS measurements. This finds applications in futuristic stealth research providing portable, economic, scalable, user friendly solution for RCS measurements in realistic environments.

Ground Penetrating Radar (GPR) uses electromagnetic waves to image subsurface features nondestructively. It's applied in archaeology, civil engineering, and environmental assessment. A GPR system includes an antenna emitting pulses into the ground, bouncing off subsurface interfaces and returning. This paper presents a Vivaldi Antenna designed for GPR, with a bandwidth of 1.1 GHz (0.39 to 1.5 GHz). Simulated and experimental results for return loss and gain are provided, validated by practical testing with a Vector Network Analyzer (VNA). The antenna effectively detects subsurface objects, showcasing its potential for diverse GPR deployments, emphasizing versatility and adaptability for geophysical explorations.

A cost-effective solution for Beamforming in miniaturized S-Band Radar applications is presented in this paper. To achieve this, Beamforming Front End consisting of 4 channels powered and controlled by a Power and Control Unit (PCU) is developed. A linear 1 x 4 sub-array is designed as the primary radiator for each channel. The proposed RF chain consists of Mixer, Phase Shifter and Power Amplifier in each channel. The beamsteering mechanism is demonstrated for various steer angles. The cost of the designed module is compared with popular Analog Beamforming (ABF) Integrated Circuits (ICs) in market and found to be drastically reduced.

This paper presents a robust plot to plot level fusion based tracking approach employing an Interaction Multiple Model (IMM) Kalman Filter framework for combining data from Primary Radar (PR) and Identification of Friend or Foe (IFF) sensors. Unlike track to track level fusion based tracking methods, this approach centrally processes correlated plot data from these sensors using IMM Kalman filter to generate comprehensive track estimate. The efficacy of this fusion approach is validated through series of simulations considering different target motion dynamics. The use of IMM Kalman filter empowers this approach to deal with manoeuvring targets dynamics effectively.

This paper describes a method which eliminates requirement of testing Satcom On The Move (SOTM) terminal on actual field conditions by emulating vehicle motion in lab environment using presented three-axes vehicle motion emulator. A series of measurements were performed to establish the motion profiles under various speed and terrain conditions. The measurement set up using INS/Dual GNSS is described and results for a maximum vehicle speed of 40 km/hr. over rough terrain are presented. The angular acceleration data was further filtered to remove high frequency components. Based on these results the motion specifications for the motion emulator were frozen.

This paper presents the design and development of a compact E-plane sectoral waveguide power combiner at Ku-band operating from 13.6 GHz to 15.6 GHz. The proposed 4-way in-phase power combiner involves only 2 design parameters and achieves a measured return loss better than 15 dB. The measured amplitude imbalance and phase imbalance are within 0.65 dB and 6 degrees respectively. The total power combining efficiency is better than 82.5 % over the entire band of operation. The E-plane power combiner is proposed to be used in Ku-band satellite communication applications.

ISRO's initiatives leverage satellite technology to deliver remote healthcare and education. An indigenous Learning Management System (LMS) empowers educators and medical professionals by facilitating virtual classrooms, training programs, and seamless interaction, overcoming geographical barriers in remote areas. Additionally, the inherent multicast capabilities of satellite communication offer significant advantages, reduced network congestion, and improved scalability, critical factors for delivering educational and medical content to geographically dispersed audiences. A satellite-based LMS that leverages multicast can be a highly effective solution for ensuring equitable access to education and healthcare in remote regions. This paper explores the design, functionalities, and challenges of this LMS.

This paper presents the design and implementation aspects of JESD204B protocol based multi-gigabit digital modulator for satellite to ground data transmission link. The paper brings out the complexity and challenges involved in the design. This digital modulator comprises of RF-sampling digital to analog converter, FPGA, clock-module for synchronization and power distribution network. Apart from the hardware design, the paper discusses the software aspects of instantiating the JESD204B IP core to maximize the achievable data rate. The design supports multiple modulation schemes-QPSK, 8PSK, 16APSK and offers flexibility in terms of programmable data rates, programmable IF frequency using the same hardware.

This paper explores the potential of leveraging millimeter-wave (mmWave) channel coding techniques to enhance reliability in 6G high-throughput satellite communications. With the increasing demand for high data rates and low latency in future wireless networks, mmWave frequencies have emerged as a promising solution to achieve ultra-high throughput. However, mmWave communications are susceptible to atmospheric attenuation and fading, posing significant challenges to reliable data transmission. This paper investigates the application of advanced channel coding schemes, such as Turbo codes, LDPC codes, and polar codes, to mitigate the effects of channel impairments and improve the reliability of mmWave communications in 6G systems.

This study introduces a novel MIMO detection strategy using Orthogonal Time Sequency Multiplexing (OTSM) modulation, specifically designed for Aerospace and Defense networks. It employs maximum ratio combining (MRC) to improve signal integrity by addressing multipath effects and inter-antenna interference, crucial under typical hardware constraints like carrier frequency offset (CFO). The method includes precise sub-channel estimation and an optimized frame structure that reduces interference and simplifies parallel processing. These enhancements decrease system complexity and enhance performance. Empirical results demonstrate the robustness of the Single User (SU) MIMO-OTSM system in spatially correlated environments, highlighting the strategy's potential to enhance military communications significantly.

This article proposes a millimeter wave circular patch microstrip antenna. The design illustrates a circular patch antenna which bears a range of 19.4-110GHz having a bandwidth of 90.6 GHz and having high resonance at frequencies of 51 GHz, 61.5 GHz, 71.8 GHz and 101 GHz. It depicts a good impedance matching at these frequencies, a decent gain and a directional radiation pattern. The material FR4 is utilized for designing the substrate of the antenna. The antenna shows a simulated gain of 8.8 dB, 8.9 dB, 7.7 dB, and 8.1 dB at the above specified operating frequencies.

For enhanced software modularity and maintainability, while meeting the exceedingly complex system requirements, a Domain Specific Language (DSL) was developed for the safety related computer system- Emergency Core Cooling System Test Facility, in a nuclear power station. This conception facilitated accurate development of test sequences directly by domain experts possessing limited familiarity with computer programming aspects. This unique DSL-based programming approach and exhaustive closed-loop black box testing enabled accurate tuning of variabilities, speedier software development, and ease of future modification. Considering the stringent atomic energy regulatory requirements, this also duly saved on development effort and software qualification timeline.

In the evolving cybersecurity landscape, the surge in cyber threats necessitates innovative defence mechanisms. Proposed work explores the integration of ML methods into Intrusion Detection System (IDS) Senspy tool. Senspy, an adaptive IDS software incorporates ML techniques like k-Nearest Neighbors (KNN), Random Forest and Logistic Regression, to enhance its detection capabilities of cyber threats. It's beneficial for recognizing outliers or unusual patterns in network traffic. By employing ML techniques, Senspy excels in detecting and identifying various cyber-attacks, surpassing traditional IDS capabilities. The system demonstrates robust performance, particularly with Random Forest algorithm achieving over accuracy and an F1 score of 99.6%.

This paper introduces an innovative approach that utilizes n-gram modeling, K-Means clustering, and advanced statistical techniques to examine the API sequence patterns of Windows applications. By extracting API calls of applications using Cuckoo Sandbox, we create n-grams to capture complex API sequence patterns that offer a contextual understanding of application behaviors. The Elbow method helps to determine optimal clusters, which are then analyzed using K-Means clustering and validated by silhouette scores. Our research focuses on understanding behavioral patterns across benign applications, enhancing both cybersecurity strategies and software analytics without concentrating solely on malware detection or classification.

Aerial imaging has profound applications like mil- itary surveillance, Earthquake assessment, Aerospace etc. Often due to sudden weather fluctuations there is variations in visibility. In this paper a CNN based architecture is proposed which re- moves the haze without much degradation in colour and contrast of the image. The Proposed model is trained on RESIDE (OTS) dataset and provided a 66%, 65%, and 9.15% improvement in PSNR, BRISQUE and Entropy respectively when compared with the best of the available haze removal techniques. Also the model has shown 25% reduction in the computational time making it ideal for Real time applications.

This research explores the potential of using drones integrated with AIML for remote animal darting. It proposes drone-based gimbal mounted gun beneath the drone with automated AI target locking system. Which allows precise movement of the gun, facilitating dart deployment, ensuring accurate and efficient darting for the purposes like wildlife vaccination program, dart and research program, capture and relocation, medical intervention, tranquilization during human wildlife conflict. This reduces the risks associated with close human-animal encounters and minimizes stress for the animal and can benefit both animal welfare and human safety in wildlife conservation, research, and intervention efforts.

The optimal characterization of operating conditions in aerospace subsystems is pivotal for ensuring optimal performance, safety, and reliability of aircraft. This paper explores an unsupervised way of selecting the best features of one such subsystem CAC (Cabin Air Compressor) which can then be used to study predictive maintenance, fault isolation etc. A combination of centroid based, density based and distribution-based clustering has been applied in this study.

A spacecraft pyro chain includes a power source, pyro initiator circuit (PIC), and pyro device. PICs are crucial for isolating the pyro device from the power source until needed and ensuring the correct fire current during operation. MIL-STD-1576 outlines fault tolerance criteria for preventing accidental firings. This paper discusses implementing breaks using Electro-Mechanical Relays (EMR) and Solid-State Relays (SSR) and presents five PIC design options conforming to MIL-STD-1576. It includes a risk analysis of each design and recommends the best circuit for both unmanned and manned spacecraft, ensuring minimal risk of inadvertent operation in all conditions.

This paper talks about Radiation Hardening by Design of switched-capacitor based buck converter containing extremely sensitive analog and mixed-signal circuits, namely current reference, VCO and switching signal generator. Using radiation emulating circuit it has been observed that functionality of the said circuits are affected by radiation strike which in turn affect performance of the converter. This paper explains the issues introduced by radiation induced perturbations. Subsequently, we have proposed modification in the aforementioned circuits, which collectively improve robustness of the converter performance against radiation effect. As a demonstration, we have designed a 2:1 buck converter in a 65nm technology node.

In this paper, we present an On-chip switched capacitor-based DC-DC buck converter topology for embedded applications, providing very high driving capability maintaining high efficiency and low output ripple. The Converter is constructed using multiple identical units controlled by high-speed non-overlapping rotational time interleaving (NRTI) switching signals. A prototype converter has been designed in 65nm CMOS Process to get 1.15 V output from 2.5 V input supply with a driving capability of 230 mA maximum load current. This converter containing ten identical units delivers a peak efficiency of 81.35% using a total 1.55nF capacitor and output ripple below 14 mV.

Active sonar systems detect targets by transmitting acoustic pulses and measuring the time of echo. In this paper Sonar Power Amplifier (SPA) that uses Multilevel Converter (MLC) topology is explained. This design enhances reliability, as failure in one bridge only reduces power, not disabling the output. MATLAB/Simulink simulations were carried for a nine level MLC based SPA for military sonar applications and results are presented.

Active SONAR transmitter system uses power amplifiers (PA) to increase the amplitude of sonar control signals, which ultimately excites the underwater projector load. The underwater projector offers complex impedance to the SONAR power amplifier (SPA). An impedance matching network is added to improve the power transfer from the SPA to the transducer. This paper reviews various SPAs that drive the projector load for underwater applications. The design constraints of the SPA's used for transmitter applications were discussed to qualify the sonar PA's. Further, some of the recent developments on SPA's are discussed to showcase the benefits of the technological innovations.

Aerospace vehicle is connected to the ground system through umbilical connectors. Before connecting the umbilical connectors to the flight worthy system, it is essential to test and cleared the ground system. Umbilical Test Jig (UTJ) with passive resistors is not able to simulate the actual power of aerospace vehicle sub-systems. The Automated Umbilical Test Jig (AUTJ) incorporates a programmable electronic load which can simulate the actual power requirement of aerospace vehicle sub-systems and measure the values. The present paper deals with design and realization of Programmable Electronic Load (PEL) based on active load and microcontroller (MSP430F6659).

Object detection in satellite imagery has become increasingly important in remote sensing surveillance applications, where the detection of aircraft is very useful. However, efficient detection of aircraft presents numerous challenges including variations in size, aspect ratio, orientation and complex background environments. Using deep learning techniques, we optimize object detection frameworks, feature extraction networks and hyperparameters for enhancing precision while minimizing detection time and achieve an AP score of 0.91. Additionally, our high speed hardware based system is optimized for near real time network deployment, achieving a notable frame rate of 46 fps on Zynq Ultrascale SOC based hardware.

This paper introduces a framework for automating the analysis of seismic images, which is essential for geological studies. Leveraging the intersection of Computer Vision and Geology, it addresses the scarcity of automated solutions in this domain. Developed within the Reflection Connection challenge, the framework facilitates query-based retrieval of seismic images and identifying structural features. Techniques such as fine-tuning pre-trained architectures and employing one-shot classification methods were explored. Additionally, a novel data augmentation method, Slice Shuffling Augmentation for Geological features that enhanced the model performance was developed.

This paper proposes RS-A2M unsupervised pipeline for segmenting RS Earth observation data, addressing the limited availability of annotated datasets. Utilizing vision transformer backbones and zero-shot detectors, the Attention to Mask (A2M) method performs segmentation without class-specific training. Validated on NWPU VHR-10, it achieved comparable performance to the computationally expensive Grounded SAM pipeline with 30x fewer parameters. Evaluated using class-wise IoU metrics, it demonstrated improvements of 3% for bridges and 26% for vehicles. For airplane, the IoU recorded is 39%, with potential for further improvement through hyper-parameter tuning. This unsupervised approach can be further exploited in target recognition and segmentation domains.

Monitoring driver fatigue is critical in safety-critical domains like defence vehicles, aircraft, and commercial transportation to ensure safety and efficiency. Operational errors due to cognitive impairment, physical fatigue, and distractions are major causes of accidents. Our real-time fatigue monitoring system assesses users' physiological and behavioural states, including head movements, to detect fatigue and distraction. Human studies validate its effectiveness in capturing facial features and detecting fatigue with minimal data loss. This non-intrusive solution can be customised and deployed across diverse driving scenarios to enhance vehicle crew performance and safety.

Efficiently detecting anomalies in spacecraft data poses a significant challenge in modern space missions. We introduce Spacecraft Anomaly Detection using Deep Learning (SADDLE), a novel transformer network-based model tailored for spacecraft anomaly detection. SADDLE leverages an attention-based encoder to analyze telemetry data, capturing broader temporal trends critical for anomaly identification. It utilizes self-conditioning for robust feature extraction across multiple telemetry modalities. Additionally, SADDLE leverages Meta Gradient Descent to adapt faster to spacecraft data characteristics, simultaneously enabling effective training with limited anomaly examples. Extensive evaluations conducted on spacecraft datasets demonstrate that SADDLE outperforms all existing methods while significantly reducing training time.

Real-world image degradations differ from ideal conditions, where common deep learning models often rely on bicubic interpolation to synthesize low-resolution counterparts. However, the generalizability of these trained models across diverse image datasets with varying distributions is still being determined. To address this challenge, we propose DRSR, Degradation Representation for unsupervised Super-Resolution specifically designed for real-world remote sensing images with unknown arbitrary degradations. The network demonstrates robust generalization capabilities across additional datasets, encompassing both "Ideal" and "Non-Ideal" scenarios. It particularly targets image datasets facing two key limitations: the absence of ground-truth high-resolution images and the presence of arbitrary degradations.

Unsupervised learning algorithms prove robust on hyperspectral images (HSI) with unavailable ground truth. We have used unsupervised learning models on the HSIs obtained from the surface reflectance data from the Earth Surface Mineral Dust Source Investigation (EMIT) Imaging Spectrometer. The abundances extracted from the proposed unsupervised method have been illustrated as clusters of where a particular endmember is located in the region of interest. The processing steps utilise a proposed 3-dimensional unsupervised clustering algorithm and generate a map of differently classified areas. Furthermore, various modified silhouette indexes have been used to evaluate clustering, which in this research is 0.91.

We introduce an enhanced YOLOv9 model for Northern Maize Leaf Blight (NLB). Our improvements to the loss function, neck, and backbone maximize feature extraction and increase detection precision. Lightweight convolution operations are made possible by the backbone's GhostConv and C3Ghost layers, while feature engineering is improved by the Ghostblock and C3TR modules. Revised loss function with Wise IOU enhances model resilience, while neck's multi-scale fusion improves feature integration. The experimental results showcase that our proposed model attains an accuracy of 86.1% mAP@0.5 on the NLB dataset, a 3.1% increase compared to the original model.

In this paper, we propose our new concurrency based model for Spacecraft Data Processing which uses concurrent threads in system memory with data buffers for message passing. Under different sections relevant to data processing, we compare our existing design with the proposed design. We start with an introduction followed by design details of the proposed Concurrency Based Model, Processing Pipeline Definition, Data Buffer Initialisation, Buffer Capacity and Concurrent Processing Instances. Further, we touch upon the robust Acquisition Module Design. Finally we perform a performance comparison between our existing and new models with respect to processing time followed by concluding remarks.

Real-time monitoring of launch vehicle acoustics ensures structural integrity and payload safety during flight. One-third octave analysis, as per ANSI S1.11 class 2 standard, is implemented in an acoustic processing unit. However, the resource-intensive nature of this analysis poses challenges for high-speed and energy-efficient systems. To address this, an algorithm is proposed which leverages the advantages of octave property and employs sequential band pass filtering with decimation, reducing computational complexity and minimizing processing time. To achieve higher dynamic range, oversampling followed by digital filtering was implemented. Efficiency is quantified, focusing on acoustic pressure excitations up to 4 kHz.

Introducing WANI, a Text-to-Speech (TTS) model designed to generate highly realistic, multilingual and lifelike audio. WANI utilizes a Transformer based architecture, leverages encodec and AudioLM. It is trained with over 1000 hours of audio data and provides immersive audio experience, especially for Indian languages. In airborne surveillance, where quick choices and effective communication are essential, use of WANI for data interpretation, multilingual communication and achieving overall operational effectiveness can prove to be of vital importance. The WANI system has obtained an average EER (Equal Error Rate) similarity score of 0.879 in the range of [-1, 1] with multilingual support.

Signal to Noise Ratio (SNR) is one of the performance metrics for remote sensing electro-optical payloads. In ocean imaging payloads, sea surface reflected signal is very feeble, which leads to very stringent electronics noise budget to maintain the high SNR requirement. In Ocean Color Monitor-3 payload, SNR budget is ~ 650 to 10000 after digital processing. Camera electronics (for 13 spectral bands) is developed to provide 12-bit radiometric accuracy with onboard programmable processing capabilities like frame oversampling, frame/spatial binning, Time Delay Integration (TDI), compression and CCSDS formatting. This paper discusses the challenges in the design and development of camera electronics.

Remote sensing data can be used instead of conventional methods to collect image data from multiple satellites with acceptable spatial and temporal coverage. The proposed study makes use of Landsat 8 Operational Land Imager (OLI) data. The relationship between reflectance retrieved from Landsat 8 OLI data and in-situ data is established through the application of machine learning model. The dataset is made up of Landsat-8 band extractions for water quality features. Water with high turbidity is predicted and verified using in-situ data that was gathered within the chosen temporal and spatial limits.

Identifying objects from satellite images can be challenging because of their varying visible qualities, hampering their value in some scenarios such as urban planning or responses to emergencies. The ability to detect vehicles and other elements in satellite imagery can give vital information on latest military developments of adversaries, especially when planning for military operations. This study addresses the detection of military objects with more accuracy by studying YOLOv8 with optimized YOLOv8 architecture improving real-time object detection capabilities.

Urban expansion monitoring is essential for understanding and managing the dynamic growth of cities. Recently, deep learning (DL)-based semantic change detection (SCD) techniques have emerged as powerful tools for accurately monitoring urban expansion using satellite imagery. This paper offers comprehensive overview of the recent advancements in urban expansion monitoring through DL-based SCD techniques. It covers various publicly available SCD datasets and assesses performance, advantages, and limitations of existing DL-based SCD architectures, categorized into three types. Furthermore, the paper discusses the challenges encountered in DL-based SCD techniques. Finally, it outlines future research directions in urban expansion monitoring using DL-based SCD techniques.

Recent AI advances, like Transformers, Conformers, Residual Neural Networks, and EfficientNets, have exceeded expectations. These models' effectiveness relies significantly on input data. Traditional signal processing and machine learning (ML) techniques, which use key features as inputs, remain promising. However, the shift to using raw signals in end-to-end systems can hinder performance, particularly when diverse classes are grouped together. This study highlights the advantages of using a broad set of temporal, spectral, and spectro-temporal features to capture the characteristics of airborne acoustic signals. The insights from this research can help optimize model performance by fine-tuning input features according to specific requirements.

This paper presents a novel comparison of CMOS and BiCMOS semiconductor technology for Low power, ultra- low noise, Wideband reconfigurable and Miniaturized PLL chip-based frequency synthesizers. Here for comparison indigenously developed L band BiCMOS PLL-VCO chip have been used with designed and developed CMOS PLL-VCO chip. Here HBT NPN transistors specially used from Sbc18h2 180 nm BiCMOS process for Ultra-low noise and High frequency PLL- VCO chip design with better spurious rejection. Similarly, SCL Ts18SL 180 nm CMOS process has been used for the design and development of wideband, low power, reconfigurable (L to S band) PLL-VCO chip design.

This paper describes the Design and Realization of RFSoC FPGA based Multi-channel Data Acquisition and Digital Beam former system. This paper describes a novel 64-channel Data Acquisition system designed using XCZU49DR RFSoC FPGA which could directly digitise the RF inputs fed at 1280MHz frequency and the ADC is sampled at 2.4GHz frequency. The ZU49DR has 16 numbers of 14-bit RF-ADC with DDC and 16 numbers of 12-bit RF-DAC with DUCs. Digital Beam forming is proved using multiple drones being simultaneously detected using this DAQ and DBF.

Data acquisition systems and tele-command simulators are must-have tools required for verifying and validating any satellite payload or mainframe systems. Data Acquisition and Command Simulator proposed in this paper is designed for SAIS receiver ground testing during various phases of development and qualification. Primary purpose of this paper is to introduce readers to flexible, re-programmable, low-cost, low-power, and production-friendly DACS design suitable for multiple interface support used for satellite systems. This design focuses on developing command simulator for controlling the SAIS receiver and data acquisition system for receiving high-speed SAIS receiver data output using the SoC platform and customized GUI.

Deep learning techniques are empowering many space based applications with good speed and accuracy. The application includes categorizing astronomical data, identifying celestial bodies, tracking their movements and many more. In this paper, we present CNN models for morphological galaxy classification on hardware. CNN models namely SqueezeNet, MobileNet, ResNet and EfficientNet trained on Galaxy10 SDSS Dataset. We implement and analyze the performance of trained deep learning models on pre-built deep learning processor for Xilinx ZCU102 provided by MATLAB's Deep Learning HDL Toolbox Support Package for Xilinx FPGA and SoC Devices. The performance results are also reported in this work.

Aerial image classification is essential to intelligent surveillance and monitoring systems. Traditional computer vi- sion methods either uses computational offloading to high-end servers or edge-devices. However, unmanned aerial vehicles (UAVs) platforms have resource and power constraints. Aerial image classification is complicated and less-expensive UAVs lack processing power and cameras. Even with large-scale computing environments, methods for classifying images are difficult to apply to aerial imagery. We propose TinyAerialNet leveraging TinyML for real-time inference on a resource-constrained ESP32-CAM. The model tested on AIDER dataset, achieves 88% on-device accuracy in the micro-controller with 103.9 KB RAM and 850 milliseconds for inference.

The authors have done the Small-signal and DC signal analysis for designing a Ka-band SDR IMPact Avalanche (IMPATT) diode. In the reverse bias, we have considered an equivalent circuit of a One-dimensional (1D) junction with and without packaging parameters. Finally, the authors have studied the effects of package capacitance (CP) and package inductance (LP) on Small signal Conductance (G) - Susceptance (B) parameter and also on the optimum frequency of operation. It was observed a downward shift of optimum frequency of 2.5 GHz - 4 GHz due to package parameter at various current densities ranging between 9x107- 1.2x108 Am-2.

Millimeter-wave Sounder Payloads provide vertical temperature and humidity profile of the earth's atmosphere. They contain reflector-mounted scan mechanism for providing a cross track swath coverage. This rotational motion facilitates a continuous swath of over 1000 kms and in-situ on-board calibration as the reflector looks at earth, deep space and black-body at different positions of rotation. This paper presents and discusses a variable rate motor drive control algorithm for the Stepper motor of Scan mechanism. The scan motor drive algorithm is implemented on a FPGA based Payload Controller (PLC), which also implements the control and status monitoring functionality of sounder payload.

An Impulse Ground Penetrating RADAR (IGPR) is proposed for the Lunar Polar Exploration Mission (LUPEX). GPR achieves fine resolution, by transmitting narrow pulses which are of few hundreds of picoseconds duration. It is impractical to digitize such wideband signals using real-time sampling approach. This paper proposes a novel approach based on equivalent time sampling (ETS) to acquire IGPR signals. In this work, step delay is applied on the transmit pulse resulting in efficient hardware implementation amenable for a resource constrained space environment. This technique was prototyped on a FPGA based hardware and an ETS rate of 35 GSPS was achieved.

For human-rated launch vehicle missions and other safety critical systems, redundancy is normally provided for inputs and outputs. To select one data from the multiple systems, a voter is needed. In this work, two voting algorithms, averaging and relative divergence were implemented in Ada and formally verified using two different tools - SPIN model checker and LLVMBMC static analyser. It was seen that the performance of the relative divergence based voter is better in some cases. Although the error scenario is remote, relying solely on self-check of the input system for data selection causes the error in averaging. The major contribution in this work is the definition of a systemic procedure for formal verification of safety-critical embedded software in Ada language with custom specifications, using two approaches. The techniques were applied to a practical case study, the voting algorithms for a safety-critical launch vehicle and found to be effective in error detection.

Space vehicles can have a dynamic need to move towards a desired target dynamically. Tactical readiness in space requires such vehicles to be alert with respect to the possibility of the presence of adversarial vehicles in their proximity. Such vehicles have very limited on-board fuel that needs to be utilized very efficiently to extend the life of the vehicle or to extend the duration to refuel the space vehicle. This paper attempts a minimal energy flight trajectory by leveraging an adaptive geodesic path to reach a dynamically moving destination target location.

A Dyson ring is a hypothetical megastructure, that a very advanced civilization would build around a star to harness more of its energy. Satellite propagation is of high priority in such a vast world where distances could very well be measured in astronomical units. We analyze the ring's parameters and stability and propose a stable helical orbit around the Dyson ring influenced by the gravity of the Dyson ring and the Sun. Taking theoretically explainable values for all parameters, we describe our approach to finding this orbit and present the successful simulation of a satellite's flight in this path.

This paper proposes a solution to address the challenges posed by the increasing number of satellites in space, leading to a lack of Space Situational Awareness (SSA) and cooperation in space debris mitigation. The proposed solution involves a commercially incentivized federated system of sensors applied to a federated learning model. This approach aims to provide an accurate, up-to-date, and open-source data model to prevent collisions in space. The solution focuses on two main aspects: Federated Satellite Systems and Federated Learning. By combining these technologies, we can improve SSA, enhance space debris mitigation efforts, and promote cooperation among space-faring nations

Next-gen wireless networks could greatly enhance capabilities by integrating Unmanned Aerial Vehicles (UAVs) for real-time data gathering, especially in defense. Current UAV methods focus on energy efficiency but neglect data freshness, crucial in military operations in challenging terrains. Our proposal introduces a pioneering approach prioritizing Age of Information (AoI) and energy efficiency in UAV-enabled IoT networks for such operations. Through strategic optimization of UAV locations using clustering and Deep Reinforcement Learning, we minimize average AoI and energy consumption. Our Proximal Policy Optimization UAV Trajectory Planning (PPO-UTP) algorithm, employing Deep Neural Networks (DNNs), ensures optimal decision-making based on collected data.

With the increasing number of satellites in the Geosynchronous Earth Orbit (GEO), there is a need to develop space situational awareness tools that accurately characterize their on-orbit behavior. This paper proposes a two-step machine learning-based approach: first, mode change detection, followed by a multi-class classification model to characterize the patterns-of-life of GEO satellites. The approach utilizes features derived from astrometric data tailored to capture trends in the east-west and north-south behavior of the satellites. The model's performance demonstrated a significant improvement over the baseline models provided in the Satellite Pattern-of-Life Identification Dataset and development kit for the AI SSA Challenge.

The kinematic positioning performance of the Navigation with Indian Constellation (NavIC) in static conditions has been thoroughly investigated in this research. In this contribution, NavIC kinematic position performance has been analyzed using the data collected in the long baseline in India. Through analysis, NavIC's SPP, long-baseline kinematic positioning, and L5 signal availability are symmetrically compared with GPS. A Double-Differenced (DD) methodology-based kinematic model is introduced, revealing NavIC's centimeter-level accuracy comparable to GPS. While individual NavIC and GPS kinematic-fix performances are inferior, their combination outperforms both.

Unmanned ground stations have become popular for satellite tracking, but lack of human presence causes difficulties to address equipment failures. Predictive maintenance through equipment performance monitoring observes performance trends to detect equipment degradation and failures beforehand. This study applies performance monitoring to Antenna Control Servo System (ACSS), wherein current drawn by servo elevation motor during satellite passes is analyzed. Using a sliding window technique to process sequential data from servo logs, a stacked Long Short Term Memory (LSTM) network predicts elevation current drawn for future satellite passes. The developed model produces promising performance, achieving a mean absolute error of 0.06.

The paper discusses the methodology of transforming an Airborne Active Electronically Scanned Antenna Array(AESA) with RF manifolds into a digitized AESA. The modified design of Beamforming Unit (BFU) provides systematic grouping of the RF outputs from the bays directly to 8 digital receive channels along with 2 Guard channels which allows adoption of state-of-the-art algorithms such as Space Time Adaptive Processing for radar. This provides enhanced capability for radar detections in cluttered environment. BFU has been modified keeping the same form factor as earlier to meet the structural requirement of the Antenna array.

In this article, analysis of a miniaturized multilayer C-band patch antenna exhibiting an Impedance bandwidth of 10.6% (4.5GHz-5GHz)within 2:1 VSWR is presented. Dimension of antenna element in terms of lambda is 0.61lambda x 0.43lambda. The patch antenna characteristics analysed across frequencies shows high absolute element gain of 4.5-5 dBi and front to back ratio of 15-18 dB and linear vertical polarization with low cross polarization level of the order -30 dB. The antenna exhibits stable radiation characteristics across frequencies. A prototype antenna array of size (1×8) is fabricated to evaluate its suitability for data link application in airborne systems.

This manuscript proposes high-gain Fabry-Perot cavity (FPC) antenna. The antenna incorporates a radiating patch and PRS layer mounted above the antenna layer. This PRS unit cell adopts uniform phase distribution with reflectivity of 0.9 and -174.26° reflection phase. This FPC antenna shows -10 dB impedance bandwidth from 9.7 GHz - 10.3 GHz. The single layered PRS enhances the antenna gain, which attains 15.97 dBi peak gain at 10 GHz in the broadside direction. The proposed structure has cross-polarization well below 20 dB. The FPC antenna is fabricated and simulated performance is validated with measurement.

In this paper, a Microstrip patch based WBAN antenna is presented for military personnel remote health monitoring. The antenna is designed on a PDMS Substrate. A flat metal based single unit Split Ring Resonator (SRR) is loaded on top of the radiating patch. The designed antenna has overall dimensions of 40×38×1.5 mm3. It has an impedance bandwidth of 800 MHz. The antenna resonates at 5.8 GHz (ISM Band) having an S11 value of -40 dB and a maximum gain of 10dBi. The proposed antenna is simulated, fabricated, and experimentally tested in the lab.

In this article, a compact planar antenna array with multiple beams in the broadside and end-fire radiation patterns using the 4×4 Butler Matrix (BM) is proposed. Proposed antenna generates 4 beams in broadside direction and 12 beams in Endfire direction with scanning angle greater than 38 and 110 degree respectively within the 3.3 and 3.6 GHz band while exciting various ports of BM circuit. The beam forming network (BFN) is cascaded with a twelve-element printed dipole array and four microstrip patch antenna array to obtain multiple beams with a peak active gain of 6.9 dBi and directivity of 11 dBi.

This work describes a Balanced Antipodal Antenna (BAA) operating in the Ultra-Wideband (UWB) region for Security Imaging (SI) applications. The designed antenna consists of antipodal sections arranged on either sides of the substrate for better impedance matching as well as gain performance. The device achieves an operating range from 1.06 GHz to 14 GHz. The designed device also achieves an apex gain of 7.65 dBi. The proposed structure will be utilized at a later stage for SI imaging of targets masked by a wall using Synthetic Aperture Radar (SAR) algorithm.

In this paper, a multiband dual-mode frequency reconfigurable antenna is presented. Dual mode refers two operational modes (diode ON and OFF) of the pin diode. The design having dimension 30 mm × 15 mm × 1.6 mm and consisting of triangular patch with microstrip line feeding and loaded with four stubs and one PIN (Positive-Intrinsic-Negative) diode. When diode is ON achieved single band at 4.2 GHz with gain of 1.04 dB and when diode is OFF, triband at 5.5 GHz, 6.7 GHz, and 9 GHz is achieved and gain are 2.20 dB, 2.07 dB, and 5.83 dB respectively.

An inhomogeneous rectangular microstrip antenna on cylindrical surface is investigated here using 3D EM simulator. The rectangular microstrip antenna is placed on the intersection of two different dielectric layers. This gives more flexibility to optimize the antenna parameters in terms of resonant frequency, BW and gain, etc. In this work, the optimetric study of reflection coefficient for different parameters such as antenna length, width, and probe position are presented. Furthermore, radiation patterns for E-co pole, E-cross pole, H-co pole, H-cross pole are also presented.

A dual circularly polarized multilayer microstrip array antenna operating in K/Ka-band has been presented in this paper, wherein the Ka-band elements have been interleavingly placed with K-band elements in a shared aperture configuration. Both arrays have been formed using sequentially rotated stripline power combiner networks to improve axial ratio performance of the antennas. The antenna exhibits return loss and port-to-port isolation both greater than 20 dB, axial ratio variation better than 2 dB and boresight co-pol gain variation of less than 1 dBic over both Tx and Rx bands.

Mechanically steerable, electronically steerable and hybrid steerable antennas are some of the commonly used types of satellite communication on the move (SOTM) antennas. Low profile and wide angle scanning are one of the major areas of concern. For applications where low profile antennas are required on moving vehicle platform, multiple panels phased array antennas concept is presented in this paper to effectively reduce the height while achieving the same RF performances. The method of phase compensation for panels is also provided to resolve aperture effects. Also, the impact of overshadowing and gaps between the panels on antenna's pattern is highlighted.

This paper presents a wideband printed monopole antenna for GPS and satellite applications. To enhance gain, the antenna is placed on top of an artificial magnetic conductor (AMC) ground. The monopole antenna ranges from 0.9 to 4.79 GHz, whereas the proposed AMC is dual-band with bandwidth of ±90 ◦ from 0.9 to 2.45 GHz and 3.1 to 3.9 GHz. At 2.93 GHz, the AMC exhibits a phase change of ±180 ◦ . Peak gains are increased by 6.4 dB at 1.5 GHz, 4.12 dB at 2.4 GHz, and 3.5 dB at 3.5 GHz. The antenna is fabricated and experimentally verified.

This paper proposes a dielectric resonator antenna that is small and efficient. It uses the aperture coupling technique to improve wideband performance for Ku-band applications. The antenna that is being proposed has a small volume of 30 x 30 x 1.6 mm 3, and it is made of an affordable FR-4 substrate. At a resonance frequency of 12.92 GHz, the simulated impedance bandwidth is observed between 11.93 GHz and 14.01 GHz, with a maximum return loss of -28.2 dB. Within the operational frequency band spectrum, the suggested antenna radiates with more than 70% radiation efficiency.

A dual linear, wide band, CATF antenna feed having couple of corrugations in extended Ku-band (10-16 GHz) is conceived, designed, developed and fabricated for the measurement of payload performance of multi-beam spacecrafts in radiated mode in Compact Antenna Test Facility (CATF). The developed feed can also be used for antenna radiation pattern measurements as well. Measured results are presented in this paper and show a very good match with simulation results.

This study explores an AI-driven neurocomputational analysis method for the analysis and performance optimization of microstrip patch antennas with versatile satellite frequency bands. A specialized artificial neural network was developed and trained to process geometrical design variables such as patch length, width, and feed point location as inputs. This trained network determined the resonance frequency and bandwidth of microstrip patch antennas based on the provided parameters. The credibility of this neural network model is evaluated by comparing its performance against simulation data generated from CST Software, along with experimental findings obtained from a few fabricated prototype antennas.

In this paper, the metasurface-loaded conformal load-bearing antenna structure for defence aircraft has been discussed. The flexible metasurface is placed beneath the proposed antenna, which improves the radiation characteristics of the antenna. Analysis of the proposed antenna is performed on a conformal phantom model of an aircraft wing which shows decent performance of the antenna. The conformal load-bearing antenna structure operates on the C-band and X-band where the integrated metasurface improves the gain.

The manipulation of surface waves using subwavelength structures to convert them to leaky waves is a well established technique. These have unique properties that can generate surface waves for precise control of radiated power. Microwave holography helps compute surface properties for desired beam characteristics. Proposed antenna uses holography to compute surface reactance, supporting Fresnel design modulation. It steers beams at 45 degrees, excited by a 5.9 GHz monopole. Study on different ground plane sizes is presented. Optimized antenna is fabricated and characterized, exhibits 8.45 dBi gain with 18.10 dB return loss.

The proposed paper presents a dual-band planar composite right/left-handed (CRLH) SIW metamaterial unit cell intended for mm-wave antenna applications. The suggested metamaterial unit cell can be used for frequency scanning-based backward-to-forward beam-steering capabilities. The proposed metamaterial structure has been constructed by engraving interdigital slots on the SIW upper and the lower surface, which gives rise to two left-handed (backward) and two right-handed (forward) passbands alternatingly that accommodate dual CRLH operating frequency bands in the radiating region for the frequency greater than 27.5 GHz.

A gradient refractive index lens metamaterial for enhancement in 2.45 GHz far-field microwave wireless power transfer system efficiency is proposed. The MM unit cell exhibits a magnetic dipole and positive refractive index of 13.73 with minimal imaginary part. The GRIN lens has a parabolic distribution and improves gain by 1.93 dBi when positioned at 153 mm from the transmitter antenna. An experimental investigation of the strategy is validated by comparing the experimental data with the Friis transmission equation for a receiver distance of 1 m. The system efficiency is enhanced to 34.6%, making the GRIN MM suitable for WPT applications.

The mid-band of sub-6 GHz for 5G applications, i.e., from 3 to 6 GHz frequency band, is widely used because of its high data rate, wide coverage area and connectivity, low latency, and less sensitivity to interference. This article proposes a wideband metamaterial absorber consisting of a ring and split ring loaded with lumped resistors. The absorption bandwidth includes the bands of n77, n78, and n79, which range from 2.85 to 6.82 GHz with absorptivity of 90%. The proposed absorber provides the same absorptivity with a fractional bandwidth of 82% and is completely insensitive to polarization.

This paper presents the construction of a microwave absorber based on a single-layer metasurface, covering C and X band frequency. The structure remains unaffected by polarization angle and demonstrates good angular stability. The unit cell geometrical parameters have been optimized to generate wideband absorption in the C and X band frequency. The absorptivity response under normal incidence obtained from numerical simulation indicates a 10dB absorption bandwidth of 8.87 GHz ranging from 3.31 GHz to 12.18 GHz. The proposed structure has potential applications in stealth technology.

This work presents a highly miniaturized tunable ultra-wideband (UWB) metasurface absorber (MSA) that cov-ers terahertz (THz) spectrum from 0.1 to 7.84 THz (bandwidth = 195%) with absorptivity (A(f)) ≥ 90%. MSA is ultra-thin with a thickness of λ0/1500, calculated at 0.1 THz. Insensitivity to polarization and stability under a wide incidence angle are key features of the MSA. Variation in the chemical potential provides excellent frequency tunability. The proposed graphene-based MSA can withstand the temperature variation from 93.15 K to 403.15 K, which enables the deployment of MSA in outer space for the suppression of unwanted electromagnetic radiation.

Subwavelength periodic structures exhibit unique features that can be used in photonics applications, including cloaking, perfect absorption, perfect reflection, and negative refractive index. In our work, we study the reflectance spectra from periodic silicon pillar based dielectric metasurface in the wavelength range of 8-12 μm (LWIR) using finite element method. We demonstrate a narrow as well as broad bandwidth near unity reflection at wavelength of 9.6 and 10.6 μm, which is the primary emission lines of carbon dioxide laser. Our proposed design has potential application in sensor protection which can be applied in space technologies, aerospace and defense.

The Chandrayaan-3 Lander involves significant complexities due to the dense packing of electronic systems, including power systems, Lander electronics packages, radio frequency systems, sensors and actuators. This paper addresses challenges in system-level integration and extensive testing needed for timely spacecraft realization. It details the electrical integration team's key activities, such as layout studies, electrical distribution design, fabrication, testing and grounding implementation. Additionally, it outlines the development and execution of complex test plans carried out in cleanroom, environmental test facilities, during composite module assembly and in launch pad to ensure that the spacecraft meets all operational requirements for orbit.

The mission objective of Chandrayaan-3 was to design, realise and deploy a lunar Lander-Rover capable of soft landing on a specified lunar site and deploy a rover to carry out in-situ analysis of chemicals. Number of tests were planned namely Integrated Cold Test(ICT), Integrated Hot Test(IHT) and Hardware simulator to evaluate the sensors and actuators of lander module. This paper briefly explains the assembly, integration and testing of the module for different special tests proposed to validate the overall performance of the system which was crucial for the safe and successful landing on lunar surface.

Aditya-L1 is a complex challenging mission considering the strict contamination control aspects of the payload elements .The most challenge in this mission was to integrate one by one package and build contamination free satellite. The paper presents the details of the challenging aspects considered by the Integration team for building a satellite. Also this paper bring out in detail the activities being carried out during the realization of the Aditya-L1 Spacecraft at the System level by the electrical integration team.

This paper brings out the Spacecraft Integration and testing aspects. In case of special environmental requirements which can not be obtained in cleanroom, the test methodology differs and special needs for testing are met in special chamber. In case of INSAT3DS spacecraft, the payload detectors require cryo temperature to be powered on. Hence the spacecraft Integrated level tests for payload detectors are to be carried out inside Thermovacuum chamber with specially designed cryo cooler to attain temperature for payload detectors. The Paylaod data was verified and to meet the specified range of standard deviation, it required the corrective measures of signal lines segregation, stringent control of ground impedances and filtering using ferrite beads. This posed the challenge on Spacecraft AIT to safely handle the spacecraft and electrical interfaces as the activities to be performed on completely ready spacecraft.

Integration and testing of a Mission system of Airborne Surveillance system requires a software-controlled facility. To meet the integration and testing requirements of subsystems, a Rig for integration and Testing (RIT) facility has been designed and is being developed on the ground and will cater for end-to-end integrated testing and monitoring of LRU performance. In this article, we proposed a software centric facility comprising TC and TCCU (Test Controller and Test Command Control Unit). The Communication between TC and TCCU via the TCP/IP Protocol and equipped with LabVIEW and TestStand software. These design methodologies automate the test and evaluation process.

In any aircraft development program, testing and validating a system before installing it in the aircraft is essential. ERAS is one of the test facilities for testing and validating system architecture for aircraft electrical systems. This paper outlines the design, construction, and validation of a comprehensive test rig capable of simulating scenarios encountered during aircraft operation. The test rig incorporates various components such as bus bars, switches, and loads to mimic the aircraft environment in which the electrical systems interact. To effectively execute end-to-end testing, the entire test rig is automated regarding data storage, data control, and command transfer.

This paper presents the effect of shield height for the power amplifier module during packaging. The aim is to demonstrate the critical height of the cavity for which there are no further reflections leading to resonance. This is critical to ensure the expected performance and safe packaging of the power amplifier module. The analysis performed captures the electric field at different heights and the impact on S-parameters. The effect of various materials used for shield and product enclosure is also demonstrated. This is verified through the radiated emissions test under FCC part 15-H and 15B class B limits.

In this paper, we present the dynamics and control of satellite formation where the chaser satellites fence a target satellite. Using velocity impulsive control the chasers are guided towards the desired relative positions for the general elliptical planar formation. Next, a control strategy for the chasers is proposed for tracking the target satellite, wherein they orient their sensors towards the target satellite. Numerical simulations are done to validate the efficacy of the methods and proposed controller.

Effective path planning is crucial for autonomous flying robots in 3D spaces. This study analyzes A-star search and RRT algorithms for guiding flying robots independently. By assessing route length, pathfinding time, and cost, we highlight algorithm strengths and weaknesses. A-star consistently finds shorter paths faster than RRT in grid setups, but RRT has a lower computational cost. Moreover, RRT's cost increases linearly with maze size, while A-star's costs grow exponentially. These factors are essential in selecting a controller for the free-flying robot, aiding in real-world applications in autonomous flying robot navigation.

There have been attempts to detect spacecraft maneuvers from determined states by comparing Keplarian parameters/orbital energy. The maneuver is detected if unexpected changes in the parameter values correlate with maneuver history. This study expands the problem to simultaneous maneuver-time and Delta-V estimation. The maneuver-time and velocity at time of maneuver estimation is posed as an optimization problem, which utilizes the Lambert problem by considering two position vectors at the time of maneuver and at an epoch after the maneuver. The estimate of Delta-V could act as a critical parameter that can provide safety and effective monitoring of space assets.

The rapid expansion of space exploration and human spaceflight has presented new challenges and opportunities for reliable and autonomous close-proximity maneuvers. Bio-inspired AI algorithms are a class of efficient algorithms that incorporate biological mechanisms to remove the shortcomings of traditional AI techniques. The Bald Eagle Search (BES) algorithm is one such novel method that has been developed based on the hunting tactics of bald eagle birds. This research work proposes to demonstrate the BES algorithm in the autonomous rendezvous and docking problem by generating a fuel-efficient path to reach the target point ensuring obstacle avoidance.

This paper is concentrated on way points navigation of flight vehicles with the help of joysticks. A web-based simulation environment was developed to evaluate the functionality as well as the performance of the device in the real-time scenario. The graphical user interface (GUI) of the simulation process can be accessed by a web browser through an interconnected network. At the end of the simulation, the results are extracted into a file for deeper analysis.

Inter-Satellite Links (ISLs) network is being deployed in the Global Navigation Satellite Systems (GNSSs) Constellation for auto-navigation, precise orbit determination and on-board clock parameters estimation purposes. It significantly reduces the need for ground stations and provides telemetry, telecommand, and ranging information in near real-time. We consider the elevation angles of all ISLs as system parameter for ISL scheduling strategy. We cluster the ISLs having similar signature and accordingly assign the time slots. The link scheduling strategy minimizes Position Dilution of Precision (PDOP) while optimizing ISL scheduling. The proposed methodology has low complexity and suitable for all GNSS satellite constellation.

The increasing adoption of technologies dependent on Global Navigation Satellite Systems (GNSS) services has prompted many countries to develop their own navigation, positioning, and timing (PNT) systems. Spoofing GNSS signals is a significant security issue as it can undermine the reliability of GNSS positioning and timing services. In this paper, we analyze the efficacy of the Navigation Message Authentication (NMA) schemes proposed for GPS (USA) and Galileo (Europe). We demonstrate the ineffectiveness of the Chameleon hash key-chain proposed for GPS signal authentication and establish that standard digital signatures offer better performance than Chameleon hash key-chain in this context.

The advent of Global Navigation Satellite Systems (GNSS) unlocked innovative applications in remote sensing and Earth observation. Among these, GNSS Reflectometry (GNSS-R) stands out as a powerful technique, enabling precise measure- ments of various Earth surface parameters, such as soil moisture, sea surface roughness, etc. This paper outlines the architecture details and development of GNSS remote sensing receiver and digital subsystem in particular developed for ISRO's first on-board GNSS reflectometry mission. The system comprises of Antennae, RF front-end, digital signal processing unit for data archival and on-board processing, and a communication interface for integration with GNSS receivers and spacecraft subsystems.

In this paper, an approach has been proposed for detecting objects using deep reinforcement learning. it involves training an agent to interact with its environment and learn a policy for object detection that maximizes a reward signal. A deep Q-learning algorithm has been used to train the agent to detect objects in images. The agent receives a reward for correctly identifying objects and a penalty for incorrect. For detecting an object, a dynamic method has been tried on the PASCAL VOC 2012 data set. The results demonstrate that this approach reaches a comparable performance level with less labeled data.

An improved convolutional neural network (CNN) with skip connections and a bottleneck layer is introduced in this study with the aim of hyperspectral image (HSI) denoising. We used Total Variation Chambolle filtering on dataset obtained from the Chandrayaan-2 mission and split the large HSI cube into smaller ones to train our model quickly. By suppressing noise and preserving crucial spectral and spatial information, our methodology can retrieve features from HSIs. We evaluated our proposed methodology using performance evaluation metrics such as Spectral Information Divergence, Peak Signal-to-Noise Ratio, Structural Similarity Index Measure, and Spectral Angle Mapper which performed better in denoising.

Estimation and Prediction of the next states in radar tracking, revolved around particle filters and Kalman filters. There is vast scope to improve the prediction of the next states in ADS-B and the IFF systems. In the era of system modelling, to find a suitable model, this study explores the customization and implementation of machine learning algorithms to replicate Kalman filter state estimation. The open-source ADS-B GPS data, latitude and longitude, utilized as a dataset for Training and Testing. Three different machine learning algorithms are considered, with input efficiency being assessed precisely by using dual models and 10-fold cross-validation techniques.

NIR images, capturing light beyond visible spectrum, are useful in remote sensing, astronomy, etc. Converting them to RGB format makes them better to interpret for humans. This paper introduces a novel approach for NIR to RGB image colorization using GAN. Our primary contribution is a Conditional Generative Adversarial Network (cGAN) with an enhanced Attention UNet serving as its generator. With this model, we have achieved an Angular Error of 15.55, PSNR of 16.41 and SSIM of 0.69 which is comparable to the other prepared models' like pix2pix & Attention UNet as well as more visually appealing than all of them.

Diabetic retinopathy (DR) damages eye blood vessels and causes issues that lead to blindness if it is not detected at an early stage. The retina data set is used which consist of 25000 retina images, and for training, 70% of the of the images were used and the remaining 30% were taken for testing. To detect diabetic retinopathy, different types of models like Xception, Densenet201, IR-CNN, InceptionV3, and Resnet50 were used for training. After performing the experimental results, Xception performed with an accuracy of 99.7%, a precision score of 99.8%, a recall score of 99.6%, and an F1-score of 99.7%.

This study presents a novel Deep Learning method using YOLOv9 to identify lunar features such as craters, boulders, and plains accurately from Chandrayaan-2's Optical High Resolution Camera images and a CNN model called EfficientNet with LSTM for generation of descriptive captions for the identified features. The proposed integrated model of YOLOv9 and EfficientNet-B7+LSTM, will help in automated analysis of lunar topography. The information generated from the proposed model will be helpful for applications such as identification of safe landing zones for future lunar missions. Model recorded an accuracy of 91.3%, precision of 92.8%, recall of 97.1%, and mAP of 0.91.

Radio Frequency Interference (RFI) is a most challenging problem faced nowadays for engineers which are dealing with RF and Microwaves, mainly in satellites communication, weather radars and synthetic aperture radar images. This work utilizes the power of Convolutional Neural Network (CNN) for RFI classification from weather radar PPI images and Deep Denoising Convolutional Neural Network (DnCNN) techniques for its mitigation. This study is a first of its kind in India which gives classification and mitigation solution for combating RFI in radar systems using deep learning techniques.

Edge-AI capabilities for on-board processing in space-based platforms has emerged as an important research field. Semantic segmentation, an important vision-based AI technique can assist with tasks like in-orbit servicing and space debris removal missions. Challenges for in-orbit semantic segmentation include structural variations in various spacecrafts, differences in patterns/textures for body and solar panels, low-lighting leading to significant SNR requirements, direct solar glare and complex background. To address these issues, we propose MANet for performing segmentation with MiT-based backbone. The network achieves state-of-the-art results for SPARK2024 dataset i.e. IoU scores of 0.9977 and 0.9974 for training and validation sets respectively.

In certain communication systems, single-ended signal transmission over fiber links with Erbium Doped Fiber Amplifiers (EDFA) undergoes heavy distortions due to transient effects, caused by the slow gain dynamics of EDFA. This distortion occurs when the input digital signal frequency is comparable with the lifetime of Erbium ions, leading to data misinterpretation at receivers. This is very critical during control and synchronization signal transmissions. Conventionally, long-distance communication prefers differential signals due to its common mode noise rejection capability. In this work, we report a method utilizing differential signals and explains how transients are nullified due to its inherent signal characteristics.

Compact antenna test facility (CATF) is widely used for characterization of antenna parameters and payload parameters in radiated mode. The radiated mode characterization of payload in CATF usually calls for mounting of two different feeds, one for uplink and another to cater downlink frequency. The two feeds will be placed at an offset from focus, as the test range has a single fixed focus. To circumvent this problem, an ultra-wide bandwidth (64 %Bandwidth), 3.6-7 GHz, C-Band CATF feed which covers uplink and downlink in a single feed is designed. In this paper, design details, and measured results are provided.

A Circular polarized parabolic reflector antenna with prime focus axial mode helix feed for C Band satellite telemetry reception from communication satellites in 3.6 GHz to 4.2 GHz frequency range during launch phase is presented. The antenna was designed, simulated, fabricated and tested. The fabricated antenna has 14 dB return loss bandwidth of 850 MHz from 3.6 GHz to 4.45GHz and simulated peak gain greater than 29 dBi with beamwidth greater than 4 deg over entire band. The fabricated antenna is deployed at Satish Dhawan Space center (SHAR). First time, the realized antenna was successfully used during GSLV F-14 mission.

Surveillance Radar mounted on the aircraft is backed up with high-power rack mounted electronics packed in boxlike structures called Line Replaceable Units (LRUs). Cooling of the LRUs is an incredibly important part of Radar operation, as it impacts their performance, longevity as well as noise levels. Design and development of the Liquid Cooling System (LCS) has to meet the individual cooling requirements of LRUs. This paper presents about the details of the design and development of the LCS that can handle approximately 125 kW heat load generated from radar electronics. Incremental approach is followed in design and development of LCS

The development of Solid-State Switch with a high current rating in hybrid compact package, poses significant challenges in fabrication, testing and qualification for space applications. These challenges have been effectively addressed by incorporating advanced packaging materials, bonding materials, and improving thermal management through optimal layout design techniques. The paper focuses on articulating the advantages of Solid-State Switches over electro-mechanical switches, detailing the design approach and outlining fabrication and qualification processes. The successful development of the Solid-State Switch is a testament to the excellence of HMC endeavour, meeting all requirements to operate satisfactorily in harsh conditions of space.

The paper proposes a novel technique for the estimation of the velocities of exoplanets based on transit photometry using the slope of the transition light curve. An analytical expression is derived for the normalized velocity of the exoplanet as a function of the slope of the relative brightness. It is shown that the proposed technique is general, and works both for equatorial and non-equatorial crossings by the exoplanet. The theory is verified using transit data for the Trappist-1 system. The idea is extended to potential defence applications and velocity estimation of resident space objects.

Marine debris present a severe, escalating threat to oceans and coastal ecosystems, requiring effective monitoring and detection. This work proposes an automated marine debris detection system utilizing satellite imagery data from the MARIDA dataset, sourced from Sentinel-2. Advanced AI techniques are leveraged to analyze high-resolution satellite imagery, and the models are trained to facilitate the identification/tracking of marine debris across various water bodies. Experiments reveal that the machine learning models form a robust baseline, while the UNet model achieves improved precision. The proposed Attention-activated UNet model achieved the best performance, particularly in challenging conditions.

Service latency reduction and quality improvement are achieved by Mobile Edge Computing (MEC) through offloading computation-intensive tasks to network edges. Cube satellites (CubeSats) act as assisted MEC servers for large-scale, sparsely distributed user equipment (UE). Considering UEs' limited computation and energy capacities, this paper investigates a collaborative mobile edge computing system with multiple CubeSats. We address task offloading to minimize execution delays and energy consumption via CubeSat task allocation management. A Markov decision process and a cooperative multi-agent deep reinforcement learning framework with an actor-critic algorithm are employed. Results demonstrate our method outperforms other optimization approaches.

This paper presents a compact planar T-junction power divider designed specifically for low-band 5G base station applications. The proposed power divider offers an operating bandwidth spanning from 500 MHz to 2000 MHz, covering crucial frequency bands such as n71, n5, n44, and various lower frequency 5G bands. Implemented on a low-cost FR4 substrate, the power divider achieves remarkable compactness, with substrate dimensions reduced to just 0.12lambdag times 0.17lambdag, highlighting its suitability for space-constrained applications.

The design of a wearable antenna for the application in various fifth generation (5G) frequency bands including the lower frequencies below 6 GHz (centered at 3.5 GHz) and also millimeter-wave (mmwave) frequencies is presented in this work. The inexpensive substrate material is used for the design. The plots for reflection coefficient, gain and radiation pattern of the optimized antenna are presented here. The proposed design may be used for 5G based body centric applications.

This paper discusses the design of 5G rejection filter using a tapered section in existing WR229 waveguide for satellite ground station applications. The designed section, after inserting in the WR229, results in insertion loss of 1.15 dB max and rejection of 25-33 dB at 5G frequencies.

In the realm of 5G technology, seamless mobility relies heavily on efficient mobility management, particularly handovers (HOs). Our study investigates the parameters of A3 event and their impact on the mean edge signal-to-noise ratio (SNR), a vital but often overlooked metric. Using Deep Neural Networks (DNNs), we establish a detailed connection between A3 parameters and key performance indicators (KPIs). Our analysis highlights the dominance of A3-offset over A3-time to trigger (TTT) in influencing mean edge SNR. While DNNs offer complexity, decision tree provide a balanced trade-off between RMSE and complexity, aiding in optimizing mobility management for enhanced 5G network performance.

The Space-Air-Ground Integrated Network (SAGIN) model in 6G networks, wherein Unnamed Aerial Vehicles (UAVs) and satellites enable communication between users and Content Service Providers (CSPs), is explored in this paper. Minimization of CSP costs is proposed through UAV caching, whereby UAVs directly deliver requested content from their cache or cluster. An optimization problem encompassing user clustering, UAV cache placement, and power allocation is formulated and solved using game theory, genetic algorithms, and efficient power allocation methods. Simulation results illustrate the effectiveness of our approach in reducing CSP costs and enhancing system efficiency in 6G networks.

A compact Multiple Input Multiple Output DRA intended to operate in the n261 (27.50 GHz - 28.35 GHz) frequency band is presented in this paper. Plus-shaped microstrip-fed slots below four cylindrical dielectric resonators are used to excite the DRs, which are placed on the substrate. The 2×2 MIMO antenna has a maximum gain of 8.1 dBi. The ECC value of the proposed antenna is nearly zero. The other MIMO parameters are also obtained to confirm the MIMO performance of the presented antenna. This design can play a vital role in global satellite communication and facilitate connectivity in remote areas.

This paper presents design and development of vacuum-sealed waveguide windows at mm-wave and sub mm-wave frequencies and associated realization challenges. The vacuum-sealed waveguide windows are essential to isolate various environmental conditions required for characterization of microwave front-ends. The proposed window comprises of quarter wavelength spacer sandwiched between two epoxy-filled shims. The vacuum-sealed waveguide windows are designed at four different frequency bands ranging from WR8.0 to WR2.8 and the measured leak-rate of developed waveguide windows is ≤1x 10-8 atm-cc/s. Detailed design methodology including simulations, parametric analysis, fabrication challenges, characterization results and analysis of these windows is discussed in this paper.

Millimeter-wave Humidity Sounder (MHS) Payload in Microsat-2B satellite was launched on 10 th February 2023 onboard SSLV-D2 rocket. The MHS instrument generates valuable science data used to build the vertical humidity profile of earth's atmosphere. The Payload data is being used in Numerical Weather Prediction (NWP) models for applications like Nowcasting and Weather forecasting. The Payload comprises of a scan mechanism with reflector, 6-channel receiver and the digital systems namely Payload Controller & HPDAS (High Precision Data Acquisition System). This paper discusses the Automatic Gain & Offset Correction (AGOC) algorithm and Fault Resilient techniques implemented in Payload Controller system.

Very high absorbers are required for stray light attenuation in the space borne systems. Carbon Nano Tube (CNT) based films have been qualified for space applications. The paper provides details on the development of CNT films for space applications and a comparison between the on-board performance of the star trackers with Black Absorber Coated (BAC) baffle and very high absorber CNT film coated baffles. The analysis of the on-board star tracker data with CNT film coated baffle (in GSAT-24) and BAC baffle (in GSAT-30) shows that CNT film contributes to the improved on-board performance of the attitude sensor.

This paper describes about Electro Optic/Infra Red(EO/IR) simulation and its integration with the Mission Simulation, consist of Maritime Patrol Radar(MPR) Simulator, Automatic Identification System(AIS) Simulator, Automatic Dependent Surveillance Broadcast(ADSB) Simulator and Pollution Surveillance Suite(PSS) Simulators. Scenario generator simulates truth data of aircrafts/ships and forward to Simulation Data Service(SDS) and EO/IR Simulator. SDS sends truth data to sensor simulators as per request. All sensors simulation output along with EO/IR simulated videos output will be visualized in a single console of Multi-functional Tactical Console(MTC), which helps the Mission operators of coast guards to do their job in ease manner.

Ge2Sb2Te5 (GST), an amorphous/crystalline chalcogenide material, is a promising candidate for vertical photodetectors due to its exceptional light absorption properties and seamless integration with silicon photonic platforms. This paper explores the utilization of simulations to analyze and optimize the design of Ge2Sb2Te5 vertical photodetectors. In the proposed method the thickness of Silicon and crystalline GST (c-GST) is optimized for the optimal performance. Two configurations are compared, evaluating the trade-off between photocurrent generation and thermally induced dark current. The results prove the trade-off between cathode current in the presence of photons and dark currents due to temperature.

In this work, rGO on silicon based X ray detector is fabricated, packaged and tested for its performance at room temperature and at low temperatures. Its performance comparison is done which shows that the device performance improves with the reduction in temperature which can be attributed to the reduction in thermal noise leading to improvement in its signal to noise ratio (SNR).

Capturing live images/videos and streaming them to ground station is one of the important objectives of satellites. Transmission of high-definition images or videos requires high bandwidth. Video compression enables transmission of high-quality video at lower bandwidth. The paper explains the implementation of low-latency live video transmission over Software Defined Radio (SDR) on an FPGA and a Radio transceiver. JPEG compression with dynamic compression control is used to send the highest quality video in the available bandwidth.

Software-defined radios (SDRs) are already widely used and often implemented in wireless and terrestrial radio frequency applications. Since these reconfigurable systems have proven beneficial, even the highly conservative and slowly evolving space sector has adopted SDRs for use on satellites and spacecraft. The increasing use of limited bandwidth and distributed satellite missions necessitates a flexible communication platform where SDR is advantageous by providing flexibility and re-configurability. Moreover, mass and cost reductions can be achieved with SDR. This paper presents a wideband SDR architecture, its advantages and disadvantages, as well as filtering solutions to further improve the performance of these systems.

Orthogonal Time Frequency and Space (OTFS) is a promising Integrated Sensing and Communication (ISAC) Waveform which has potential applications in 6G applications such as autonomous vehicles, UAV-assisted networks, etc. In this paper, we analyse the performance of OTFS-Linear Frequency Modulated (OTFS-LFM) waveform. We address the gap in literature where the sensing performance of OTFS is studied only as a single-user waveform. We show that the parameter estimation performance of the OTFS-LFM as a Multi-User waveform is critically dependent on the Multi-User configuration of the waveform. The study thus provides strategies for multi-user symbol placement in OTFS-LFM for improved parameter estimation.

Multifunctional MIMO Software Defined Radars are the state-of-the art in radar technology. Advancements in FPGAs, SoCs have enabled highly configurable and adaptable MIMO designs for improving the radar performance. We present an FPGA based OFDM-MIMO design for adaptive transmit-beamforming with capability for simultaneous scheduling of beams across OFDM sub-carriers for concurrent multi-mode MIMO operations of surveillance, SAR/ISAR imaging etc. The proposed design deviates from conventional multi-DDS design to single-DDS design for optimal FPGA resource-utilization. Our implementation in ZYNQ can be directly used in any SoC/RFSoC and is particularly useful in Airborne Radar Surveillance, automotive-radars and Integrated Sensing and Communication Systems.

This paper examines a memory polynomial model based wideband digital predistorter for 100 hops/sec, frame-based-frequency-hopped LTE signal of 1.4MHz bandwidth and at a frequency spacing of 1MHz. As a narrowband predistorter at each hop frequency is beyond the scope of hardware resources and dwell time, a wideband predistorter has been implemented. An LTE signal of 20MHz bandwidth is used for training. The training signal has a complementary cumulative density function close to the signal under test. The Normalized Mean Square Error of the LTE signal of 1.4MHz is -32.07dB, and the Adjacent Channel Power Ratio is 44dBc on average.

This paper discusses about the design and implementation of a low-cost spectrum monitoring solutions for day-to-day TTC operations of multiple GEO/GSO satellites. The spectrum analyzer data, from several earth stations, can be accessed remotely from the control centre, to enable monitoring of spacecraft telemetry. The designed FFT-SA has a max span of 40 MHz with RF front-end attenuation of 30 dB and noise floor level of -120 dBm.

This paper focuses on the Software-Defined-Radio-based miniaturized version of satellite ground station architecture called SDR-Micro-Earth-Station (SDR-MES) to support TTC operations for Geostationary and Geosynchronous spacecraft. For space missions, the ground station plays a critical role in supporting various phases of missions like the Launch and Early Orbit (LEOP) and On-orbit operations. SDR revolutionized the design and operation of satellite ground stations, combining the high performance of wide-band radio front-end with flexible FPGA-based digital backends, which can be reprogrammed using software without any hardware modifications. This paper highlights the pragmatic approach for realizing the miniaturized version of the satellite ground station.

This paper describes development of a GNU Radio based tool to design a ground station receiver for satellite communication. The proposed work focuses on observing radio frequency(RF) spectrum used by satellites to communicate with ground station. RF spectrum obtained from various satellites using proposed GNU tool is reported in the paper. RF spectrum from one of the S-band satellites named SindhuNetra(SINE), designed inhouse by PES University, alongwith RCI-DRDO and launched by ISRO was used for study, analysis and various experiments, including demodulation and decoding of telemetry data using the proposed tool with a maximum Figure of Merit obtained being 0.997.

The reduction in size of transistor every 18 to 24 months has led to improved compactness of electronic devices. However, further transistor size reduction close to an atom presents physical constraints and classical laws invalidity. This motivates the need for shift of focus towards quantum laws or phenomena and led to tremendous research interest in quantum technology both in industry and academia recently. This paper presents critical-review of quantum computing with emphasis on the core principles including quantum laws or postulates while presenting computation models, programming frameworks and their implementation challenges highlighting quantum noise, with the available infrastructure including hardware.

Our work aims to introduce an FPGA-based electronics architecture designed to enhance the security of quantum key distribution (QKD) networks. The core focus is on integrating a true random number generator (TRNG) IP in an FPGA-based QKD control electronics implemented on Xilinx's ZYNQ UltraScale+ based FPGA boards. The work presents the challenges in integrating an existing TRNG IP with QKD FPGA design, different bit and timing requirements, the subsequent speed mismatch issues, support for multiple QKD protocols (Coherent One-Way (CoW) and Differential Phase Shift (DPS)) and user-defined QKD implementations. The integrated design also supports external QRNG/TRNG over USB/Ethernet.

This paper introduces the hetero-epitaxial development of GaN/AlGaN diodes shows significant betterment in noise and optoelectronic performances. This new class of hybrid Avalanche Photo Diode (hAPD) offers advantages owing to better thermal conductivity, lattice matching and electrical conductivity. Quantum-Corrected Drift Diffusion (Q-CDD) study shows the superiority of hAPDs in terms of enhanced Quantum Efficiency (92%), Photo Responsivity (77%) and low dark current. To the best of the authors' knowledge, it is the first report on hybrid APD with GaN/Al0.56 Ga0.44 N/SiC for application as low noise Single Photon Detector in UV region.

We explore the application of an atomic Fabry-Perot interferometer (FPI) with a pulsed non-interacting Bose-Einstein condensate as a space-based acceleration sensor. We derive an analytical approximation to compute the acceleration sensitivity using classical Fisher information. In low length conditions with a high-finesse FPI and an infinitely narrow momentum width source, the atomic FPI exhibits greater acceleration sensitivity than an equivalent-length Mach-Zender interferometer (MZ). Our analysis shows that the atomic FPI could be an excellent alternative in the future if lower momentum widths were to be achieved, although MZ interferometry currently provides enhanced sensitivity under experimental parameter regimes.

The evolving field of wireless optical communication finds its applications in various fields of space, defence, underwater, and last-mile connectivity too. To achieve the aspect of higher data rates and an optimal bandwidth it is necessary to incorporate advanced modulation techniques. This research work focuses on designing a higher data rate link using a 256-QAM scheme. The design of system is done using Mach-Zehnder Modulator and was carried out in Optisystem software. This research work focuses on the designing aspect and simulations are carried out which acts as a further foundation for hardware implementation in real-time as well.

Blue/green laser communication has emerged as promising technology for underwater laser communication. PPM is one of the popular energy-efficient modulation waveform for underwater communication. Data rate of PPM modulation is limited by Pulse Repetition Frequency (PRF) of laser source. Herein, the hardware implementation of 256-ary Pulse Position Modulation (PPM) with the constraints of PRF is presented. The functional modules of PPM Waveform are implemented on a Programmable Logic (PL) part of Xilinx Zynq-7000 APSoC. Implementation result shows data rates for different values of PRF and pulse widths. The maximum data rate of 524 kbps is achieved by the PPM waveform.

This paper presents the on-orbit performance results of Lander Horizontal velocity camera (LHVC) obtained in Chandrayaan-2(CH-2) and the improvements carried out for Chandrayaan-3 (CH-3). LHVC computes velocity of Lander while descending by comparing two images using phase correlation image registration algorithm. LHVC was operated in various orbits and at various sun angles with respect to moon and the robustness of the sensor is seen in the results. Based on the Lander dynamics observed in CH-2, improvements are carried out in LHVC for minimum velocity measurement and rotation angle tolerance. The improvements are tested and the results are also presented.

Vision systems, like other deep learning-based systems, encounter limitations due to training data and struggle to handle adversarial conditions such as varying lighting and weather conditions. In this paper, we propose a knowledge distillation framework aimed at bolstering the resilience of computer vision systems under adversarial conditions. Specifically, we focus on object detection task in adverse weather conditions and demonstrate that our system either exceeds or matches the state-of-the-art accuracy levels. Our system achieves a 2% higher mean average precision (mAP@50) in hazy conditions, and 9% higher mean average precision (mAP@50) in low-light conditions, compared to the nearest state-of-the-art frameworks.

This paper proposes robust bearing data-based association method for airborne sensor tracks. This method adopts existing algorithms namely, Probabilistic Neural Network (PNN) & Global Nearest Neighbour (GNN) for efficient association. In this method, modified average of instantaneous outcome from the PNN/GNN algorithm, confidence of previous update, and number of successive hits are considered for calculation of final confidence. This method is validated using sparse, crossing, and dense target related to combat scenarios in simulated environment. PNN/GNN algorithms performs poorly in dense and crossing target scenarios. In proposed method, we have added averaging scheme post PNN/GNN outcome to increase association accuracy.

Region of interest segmentation is an important step in satellite image analysis. U-Net is a commonly adopted segmentation model, which shows good performance in many applications. However, applying U-Net to satellite images requires high memory usage, and is constrained to binary classification. To address these issues, we propose Patch Layer Adaptive Network (PLANET), which introduces dynamic layer-design and multi-class capabilities. We compared PLANET with a number of models using the MBRSC satellite dataset, and performed both qualitative and quantitative analysis. Experimental results demonstrated that PLANET outperformed other methods, achieving a mIoU score of 89.4% compared to U-Net's 79.4%.

Vegetation health assessment is crucial for sustainable agricultural practices, particularly in managing rotational grazing strategies effectively. Remote sensing technology has been used increasingly for earth observation, which includes monitoring extensive agricultural landscapes. This study introduces a novel Vegetation Index Approximation Filter, combined with K-means clustering, to advance pasture health analysis techniques. Our method can accurately classify Sentinel-2 multispectral image regions into five vegetation health levels. By integrating unsupervised K-means clustering, our approach is able to increase assessment accuracy, and provide actionable insights for optimizing pasture usage and sustainability in diverse landscapes.

Wireless sensor networks (WSNs) consist of small, battery-operated nodes deployed in remote areas. Energy efficiency is crucial due to battery recharging challenges. Accurate detection of interest areas is vital, but centralized methods create communication overhead. Near the fusion center (FC), nodes deplete rapidly, while others have ample energy. To tackle this, we propose a distributed method using the minimum volume ellipsoid (MVE) algorithm to cover infraction areas. Khachiyan's algorithm optimizes the ellipsoid's size. Transmitting this to the FC enhances network power efficiency. Simulations confirm substantial improvements in energy conservation and network efficiency, validating our approach.

The paper describes the development of highpower, low-loss, PIN diode based SPDT reflective switch with integrated driver at P-band for pulsed radar applications. The switch operates at a peak power of 100W with 5% duty cycle and is used at the output of Power amplifier to switch between H and V polarization ports of the antenna. Two such switches are also used in each chain to protect the receiver from possible leakage by ensuring minimum 100dBc isolation during transmission. Driver at 50V is used to provide complementary back bias voltage. Integrated switch and drivers fit into size of 60mmX40mmX1.6mm.

This paper presents an SPDT switch with series-shunt topology implemented in a 180nm triple-well CMOS process, utilising a switched resistive body floating technique to achieve high isolation. The utilisation of FETs with triple-well provides better performance in terms of noise, isolation, and wideband frequencies from 100MHz to 5GHz. After parasitic extraction (PEX), achieving specifications is often considered a challenge. Therefore, various layout techniques are implemented to mitigate the effects of post-layout parasitics. The proposed design accomplishes an insertion loss of 0.956dB, return loss of 11.7dB, isolation better than 45dB, and output P 1dB of 10.5dBm after PEX at 2.6GHz.

This work aims to model the near-field ultra-high frequency (UHF) radio frequency identification (RFID) scenario and evaluate the system's performance. The received power by tag or tagged object is calculated with the help of an electromagnetic simulator and measured through a commercial RFID reader. Later, the read range is compared by evaluating RSSI through measurements and power transfer efficiency through simulations. For measurement purposes, a high gain and broadband antenna is designed on a 60 mil F4B substrate, and a prototype is developed. The performance of the realized antenna is measured and compared with that obtained through simulations.

This paper presents a polarization switchable, dual-band slot antenna designed for a compact Radio Frequency Identification (RFID) reader. The proposed antenna can switch its polarization between left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The polarization switching is realized using the connection and disconnection of the metallic strip. The operational bands of the proposed antenna are 865-867 MHz (Indian UHF RFID Band) and 2.4 GHz ISM spectrum band (Bluetooth). To make the radiation pattern directional, one backed metal cavity is used. It also enhances the polarization purity of the antenna. The simulated and measured performance is reported.

A comprehensive study of a low-profile, cost-effective, miniaturized dual layered EBG backed disc shaped wearable RFID tag antenna is discussed in this paper. Employing the low loss characteristics of felt substrate, proposed EBG backed disc shaped antenna is printed on it. Proposed 4×4 EBG unit-cell array provides 42% compactness at f r=5.8 GHz. Mostly, proposed dual layered EBG backed RFID tag antenna focuses on low Specific Absorption Rate (SAR) consumption for flexible and harmless on-body applications. Moreover, the proposed dual layered RFID tag antenna is kept into a meshed human hand model to evaluate SAR value in a practical manner.

TTC RF Characterization holds significant importance within RF Checkout. As the number of satellites grow, spanning from nanosats to intricate scientific missions, the imperative for automation in Spacecraft Checkout Operations becomes increasingly evident [1]. This paper delves into the realm of automating and optimising RF Checkout through software solutions. The software interacts with various ground equipment and characterizes the RF elements with predetermined sequences for various tests. The Optimizations described in this paper lead to time reduction, error avoidance, work load reduction on the test team and ensure repeatability.

Launch vehicle checks during count down till lift off is carried out through Checkout systems positioned near to Umbilical Tower. Checkout interfaces connect checkout systems to launch vehicle through umbilical connectors. Qualification of these crucial interfaces before each launch is a tedious and time consuming process. Considering ease of testing and quick configuration, a customized FPGA based automated testing system is developed as a pilot project. This paper describes the development of hardware and software components of this system. Novel test methods suitable for faster automation are also developed. Bench tests revealed significant reduction in time taken for testing.

Triple Independent Bus System adopts triple redundancy in system design. The three independent chains require an isolated grounding architecture at both onboard as well as ground testing systems to mitigate potential ground loop formation scenarios. The article proposes an isolated checkout system design to address the onboard grounding requirements. The changes with respect to conventional spacecraft grounding architecture are highlighted with experimental results.

The Launch vehicle avionics rely on batteries for flight power, but for ground testing, batteries are impractical. Power supplies simulate batteries for each avionic subsystem, requiring complex ground systems and interfaces. During launch countdown, power must seamlessly transition from external to internal sources. This paper proposes an advanced, reliable power distribution system using a unified bus, minimizing interconnects, enhancing redundancy, and reducing mass. It discusses system configuration, design constraints, and fault protection techniques to ensure reliability during critical phases.

This paper presents a new test methodology for characterization of high power payload by using waveguide hybrid based test setup. A WR-75 waveguide hybrid is developed, qualified and utilized as a power divider in test setup to reduce the power handling requirement and better thermal management of other high power test components. Developed hybrid has 3±0.45 dB coupling and better than 27 dB isolation in 10.5 GHz to 12.5 GHz frequency band. Test waveguide routes are optimized to get better accuracy in test results. Presented methodology is successfully utilised for Thermo-vacuum testing of Ku band high power (4.8 kW) payload

This paper proposed a novel architecture for design and simulation of wideband RF Switch Matrix(RFSM). The simulation for RFSM is carried in Visual System Simulator (VSS) software. The input parameter for the simulation is derived from the COTS SPDT, SP4T and SP6T electro-mechanical RF switches. The component & the configurations are finalized based on the simulation carried out. The aim of the proposed RFSM is to carry out performance evaluation of airborne system, subsystem of Project ISR. This will facilitate the automation through reduced time, cost & complexity of the functional and performance evaluation process in the Test Rig.

Convolutional Neural Network(CNN) is popular methodology for image classification in remote sensing. However, high-resolution images from nano/microsatellites face bandwidth limitations and cloud-cover issues. Real-time cloud detection is essential due to its impact on bandwidth and playback time. Despite CNNs' success in ground-based detection, their complexity hampers real-time use on resource-limited satellites. This work introduces SICNet, a lightweight CNN for automatic cloud detection, using the Xilinx-Vitis-AI TensorFlow framework. Trained on 20,000 images, it achieves over 85% accuracy with ≤2 ms inference time on a Xilinx ZCU102 Evaluation Kit. This platform extends to applications like fire and object detection in remote sensing.

This work presents a new approach to crop quality monitoring that makes use of deep learning vision algorithms and a Single Board Computer (SBC). Our approach consists of a multi-step image processing pipeline, wherein the ROI (Region of Interest) is first identified using a specialised Vegetation determination procedure (NDVI). Furthermore, geo-coordinates enabling accurate geospatial mapping of crop quality measurements. A 5- layer CNN classifier, as well as deep learning models for leaf classification and optimised picture filtering, augmentation, and segmentation, come next. The system's real-time capabilities were assessed using an Nvidia Jetson Nano Developer kit.

Large solar flares (SFs) can disrupt radio communication and harm instruments and astronauts. Hence, it's crucial to predict SFs. However, the mechanism that triggers SFs is not yet known. We only have several physical features believed to be related to the process. This makes choosing the most impactful features for SF production important. We investigate a feature selection method based on the weights learned by a linear classifier. We use the Spaceweather HMI Active Region Patch (SHARP) summary parameters based on the Solar Dynamics Observatory's Helioseismic and Magnetic Imager data records. The records are from May 2010 to December 2019.

In cosmology, Galaxy clusters provide crucial information about the evolution of Universe. Hence identifying galaxy clusters is essential for in-depth understanding of the Universe. This article evaluates performance of four clustering methods on images from the Sloan Digital Sky Survey (SDSS). Initially features are extracted using VGG-16, then PCA is applied before applying to various clustering methods. This study evaluates the performance of K-means, hierarchical clustering, DBSCAN and Gaussian mixture model and using silhouette score, Davies-Bouldin index, and visual inspection, we assess the quality of each clustering approach. Experimental results show that except DBSCAN other algorithms perform satisfactorily.

Remote sensing technologies are integral to monitoring and analyzing Earth's surface, yet the effective extraction of information relies heavily on high-resolution imagery. This study proposes an innovative method for enhancing the spatial resolution of remote sensing images using the Enhanced Super Resolution Generative Adversarial Network (ESRGAN) deep learning architecture. Adapted specifically for remote sensing applications, the model is trained on a dataset of low-resolution and high-resolution images, allowing it to learn the intricate relationships between them. The methodology addresses challenges such as limited training data and complex atmospheric conditions, offering promising solutions for enhancing the resolution of remote sensing imagery.

The accuracy of Global Navigation Satellite System (GNSS) and its augmentation systems can suffer from various error sources, including rapid fluctuations in signal amplitude (S4) and phase (σϕ), known as ionospheric scintillations. Consequently, forecasting and mitigating these events are crucial. In our study, we examined the efficacy of three prominent statistical techniques-Exponential Moving Average (EMA), Grey Model (GM), and Holt-Winters models-for predicting scintillation occurrences. We then compared their performance with that of a deep learning-based technique utilizing Long Short-Term Memory (LSTM) networks. We found that the LSTM technique outperformed as compared to the statistical methods.

In this paper, a new ada boost-weighted extreme learning machine technique is proposed to detect ship wakes from synthetic aperture radar (SAR) images. To extract the features from SAR images a multi feature technique is proposed, which effectively extracts the pixel information. The extracted unique feature values are then imported to the adaboost weighted Extreme Learning Machine (ELM) for the classification of ship wakes. It is observed that the proposed technique is able to solve imbalanced data problems effectively and provides improved performance over other existing techniques.

In this paper, machine learning based techniques namely Support Vector Machine (SVM), Random Forest (RF) are used for detection of the scintillations and compares their detection performance with classical models namely Semi Hard and Hard detection rules. For this, we used one week data from PolaRx5S scintillation monitoring receiver which receives huge amount of data from 72 to 95 visible satellites of seven constellations. The performance of ML algorithms is compared with traditional rules by using confusion matrix and statistical parameters. The overall detection performance of ML algorithms is considerably improved and is useful for aviation and communication applications.

This work is part of a project for development of space deployable antenna designs for Prime Focus and Cassegrain configurations. This paper presents couple of feasible design concepts of 3.6m aperture antenna deployment in space. Experimental work carried-out on various test setups is presented. Based on these experiments the advantages, constraints etc. of each presented concept is discussed with respect to overall mass, cost, functionality and other such mission essential objectives. Performance and surface measurements of a realized full-scale engineering model is also presented.

This paper describes design and development of a Coarse Pointing Assembly for optical communications. The design involves a dual-axis periscope gimbal-based mechanism. It comprises of two sub-assemblies i.e. Azimuth and Elevation assembly responsible for compensating the relative motion of satellite and earth respectively. Kinematic analysis of periscope gimbal is carried out using MSC ADAMS multibody simulations. The results obtain reflect on structural feasibility and torque calculations and values. Static behavior of the design is further analyzed using CREO parametric.

The paper presents the control architecture, controller modes, gain tuning and micro gravity testing and stability analysis of 6 DOF robotic arm of Half Humanoid designed for space applications. A decentralised control architecture is followed with final execution effected through joint level position control loops. Conventional methods for gain tuning using step and frequency response analysis methods have been adopted, albeit in micro- gravity(micro-g) simulated configurations of the arm, sufficiency of which is established. The stability of the joint loops are ensured by the relative stability margins and hardware test results are presented.

Robots in space operate in highly unstructured environments and terrains due to which compliant actuators are preferred over rigid geared actuators. Series Elastic Actuators (SEAs) are a common choice for compliant actuation as they protect both the robot and the environment from unexpected collisions. The low output impedance due to the integration of a passive compliance element makes it capable of effective stable interactions with the environment. This paper describes the development of the Series Elastic Actuator (SEA) for space application through key considerations such as transparency, torque tracking bandwidth, and impedance rendering.

The current study describes a two-fingered soft robotic grasper for handling objects of varying sizes, and materials, including soft and fragile objects. The grasper's design uses compliance and underactuation to efficiently adapt its shape to the object's shape without requiring active position control. This study follows a previously presented work on the Grasper's kinematic feasibility. Further, static structural analysis is performed to analyze the launch loads experienced by the grasper model and validate its structural design. Moreover, the modal analysis has been conducted to determine the frequency of the grasper and study the mode shapes, and examine the critical modes.

The proposed system is a satellite equipped with a 3D printer, robotic arm, and sensors to detect and collect space debris. The satellite prints nets from detected waste materials, collects the debris, and feeds it into the 3D printer. When the printer is full, the robotic arm deposits the waste-filled net into the atmosphere for destruction, creating a sustainable cycle for managing space debris and reducing the environmental impact of space missions.

Deployable rigid panels have wide applications in space sector. They can be used for power generation via solar cells, communication via phased array panels and service needs via modules on space station. These panels can be designed for deployment in different ways including the commonly used active hinge driven system. However, this active hinge-based design has limitations in terms of scalability as well as need for large number of actuators. It is beneficial to have a design based on single actuation for deployment of a large array of rigid panels. In this regard, origami-based design holds promising potential.

This paper presents a wideband Low Noise Amplifier (LNA) for On-chip SAW-less NB-IoT RF receivers, covering 0.4 GHz to 4.4 GHz. It achieves low Noise Figure (NF) by integrating gate and source inductors with a resistive feedback network. The LNA demonstrates NF of 1.9 to 3.2 dB, enhancing system performance. Input matching is optimized for S11 below -10 dB. Operating under challenging conditions (FF, Vdd+10%, 125°C), it consumes 7.8 mW power. Implemented in TSMC's 65 nm low power CMOS technology, this design enhances wideband functionality and NF, crucial for NB-IoT applications.

Design and Realization of cryogenic Low Noise Amplifier at S-band is elucidated in this paper. The LNA designed was capable to work at room temperature (300K) and cryogenic environment (77K). The noise figure is measured in both temperature and an improvement of 0.25dB reduction is observed.

This study introduces design methodologies for Ultrawideband Power Amplifiers (UBPAs) using Multi-Branch Matching Networks (MBMNs). The proposed MBMNs can control the bandwidth of the wide passband through the parameter to realize ultra-wide bandwidth amplifiers. In In addition, a harmonic control network is used in the output-matching network to improve performance. Additionally, a harmonic control network improves output-matching network performance. The designed PA exhibits exceptional performance, with fractional bandwidth ranging from 195% (1.8-2.39 GHz) to 290% (3.2-3.59 GHz). At saturation, the PA achieves 57% drain efficiency and delivers a peak output power of 38 dBm, and gain is 16 dBm.

A compact and high efficiency 70W C-Band GaN MMIC Power Amplifier for pulsed applications has been designed and developed using 250 nm GaN/AlGaN HEMT based process from United Monolithic Semiconductor (UMS). It is a 2-stage circuit design with even and odd harmonic impedance matching of parallel large periphery transistors to achieve 70W at 42% efficiency over 300MHz bandwidth, with a large signal gain of 25dB using a 4W/mm process. The MMIC occupies a small area of 30mm 2 (5mm X 6mm). The design also considers conditions essential for space applications, making it suitable for usage in space based SAR transmitters.

This paper presents the design and development of an 8-way 20kW co-axial radial power combiner (RPC) for high power S-band applications. The proposed 8-way in-phase RPC achieves a measured return loss better than 15 dB. The measured amplitude imbalance and phase imbalance are within ±0.25 dB and ±6 degrees respectively. The proposed RPC is capable of providing power of 20 kW at the combined port. The EM and thermal simulations are carried out to the validate the electrical and thermal performance of the RPC. The average power combining efficiency is better than 90% over the entire band of operation.

This paper demonstrates a novel development of a Dual 16 Channel T/R Module Plank for Electronic Warfare systems operating over C-Ku band. Plank module is based on Commercial-off-the-shelf (COTS) MMICs to perform the signal manipulation i.e., phase and amplitude control. T/R module is designed with low noise figure in receive path, low power consumption in the transmit path and provides 27 dBm power output. Plank module is SWaP-Cr optimized where each T/R module is realized within a width of less than a centimeter and multiple T/R modules with digital circuitry, proper thermal management are blind mated to the Antenna Array.

A higher order (x5) frequency multiplier is designed, developed and demonstrated through this letter. Quintupler is designed using balanced multiplier topology and realized on 130nm GaAs MMIC process. Pre and Post amplification stages are included in design to achieve required conversion gain and output power. Quintupler operates in input frequency range of 1.8GHz to 2.8GHz and corresponding output frequency range at Ku-band i.e. 9GHz to 14GHz. The typical conversion gain is 14dB to 21dB with low input power level of -20dBm and achieved bandwidth is 43.5% at Ku-band.

A two state gradient metasurface based passive reflective reconfigurable intelligent surface (RIS) is proposed, which can provide upto three reflected at 12GHz. The RIS has 19×18 array of unit cells where the phase gradient is implemented along one direction. For normal incidence, three reflected beams were found to be optimum at two anomalous directions of ±56° and 0°, on the plane of incidence. The beam reconfigurability is also realized by changing the angle of incidence within 9.59°, beyond which, two reflected beams can be seen. The proposed RIS can find its application for simultaneous multi-user connectivity, especially with stationary targets.

This paper proposes an idea of direction finding using null steering methodology. A reconfigurable intelligent surface (RIS) working at 2.4 GHz is designed and capable of generating as well as steering null when placed in front of a linearly polarized antenna. This null steering can be used to make an estimate of the direction of waves reaching the receiver. An algorithm has been proposed to mathematically estimate the direction of target. Along with that a comparison between estimated and true direction is presented in a tabular fashion.

The accuracy of RF sensing is limited due to the unwanted multi-path fading in uncontrollable radio environments. As a result, the radio environments of current RF sensing techniques restrict the number of transmission channels. Instead of passively adapting to the environment, we design an RF sensing system for target localization based on reconfigurable intelligent surfaces (RISs) using compressive sensing. This system can alter environment to offer desirable propagation. For mapping the received signal to target location, we have used Alternating Direction Method of Multipliers (ADMM) algorithm to utilize target scene sparsity.

In recent years, reconfigurable intelligent surfaces (RISs) have received much attention, especially in wireless communication. Their quasi-passive architecture and ability to enhance the capacity and coverage of wireless networks by smartly altering the propagation environment without consuming additional time, frequency, and energy resources made them a favorable candidate for future wireless communication systems. Inspired by these unique features of RISs, the motivation of this paper is to analyze and adapt RIS technology to an electronic warfare (EW) environment. Our research shows that various ECM techniques can efficiently be executed with RISs and FM-RISs against FMCW radars.

This paper presents a tetraskelion-shaped frequency selective surface (FSS) geometry for tri-band applications. The design is rotational symmetric geometry by incorporating stubs within the design. The proposed structure's dimensions measure 8.4 mm X 8.4 mm. This monolayer FSS creates a tri-band result with band-pass at 2.95 GHz, wide-band stop from 4 to 10 GHz with a bandwidth of 6 GHz, and band absorber at 10.6 GHz respectively. The FSS is insensitive for both TE and TM polarizations and incident angles till 60 degrees. The proposed design is constructed with transparent material, dielectric as a SiO2, and conductor as graphene.

This paper presents a capacitance-loaded single-layer frequency selective metasurface for dual-band orthogonal linear-to-circular polarization conversion. The proposed unit cell features a modified Jerusalem cross with a connected square ring fabricated on a Taconic TLY-5 substrate. The design achieves right-handed circular polarization in Ku band (13.31-15.5 GHz) and left-handed circular polarization in Ka band (26.82-27.9 GHz) with axial ratios below 3 dB. The structure demonstrates stability up to 40° in the xz plane and 35° in the yz plane. The design evolution of structure and its analysis based on surface current and Stokes parameters are also presented to validate simulation results.

This paper presents a planar multilayer periodic frequency selective surface (FSS) for microstrip antenna gain enhancement. The structure of the FSS consists of a modified Jerusalem cross on one side and an inductive grid on the other side of a substrate. The periodicity of the unit cell is 7.25 mm or 0.24 lambda, where lambda denotes the wavelength at 10 GHz. The FSS acts as a partially reflecting surface for improving the gain of a Fabry-Perot cavity resonator antenna. The antenna shows peak gain of 16.26 dBi, return loss bandwidth of 3.5 % and average efficiency of above 90 %.

This paper presents the design and analysis of a switchable absorber/rasorber structure that is insensitive to polarization. Lossy top layer consist of lumped resistor that is separated by an air spacer from the bottom lossless frequency selective layer. The structure achieves switchable reflection/transmission capabilities and a large absorption band using PIN diodes in a slotted configuration. An equivalent circuit model has been developed to explain the geometry's operation. This switchable structure offers wide angular insensitivity up to 45 degree and is ideal for radome and wireless communication applications where it can help minimize out-of-band signals.

With advancements in GNSS technology in the last two decades GNSS receivers are finding their place in Indian launch vehicle missions also. A GNSS receiver embedded Navigation Computer (GNC) is developed for executing the functions of inertial navigation, GNSS receiver and aided navigation. The processor board is designed using COTS components for making it low cost. A set of specific self-test methods are designed for detecting any deviations from the normal working of the processor. A final switch flag is generated taking all the factors into consideration. The algorithms are validated through a set of simulation tests on target hardware.

This paper presents a modified complementary filter based sensor fusion technique aims to filter out the effects of wake, turbulence and high g maneuvers turns while maintaining good bandwidth of airdata. The proposed technique uses inertial and airdata sensors for estimating aerodynamic angle with no reliance on GPS. Unreliable AoA and AoSS data during rapid change in dynamics can affect the stability & control of the aircraft, especially in critical maneuvers. A proposed technique was evaluated for wake and high-g maneuver flight data of a high-performance aircraft. Results are compared with GPS and proposed technique found to generate comparable results.

Carrier Doppler of LEO constellations are Signals-of-Opportunity and using Doppler-based positioning technique, these observations can be utilized in a navigation solution. An algorithm for the proposed positioning technique is devised and the performance is compared against pseudorange-based positioning. A detailed analysis of DOP is provided using code and Doppler-based positioning. Further, combining LEO constellations with NavIC in a hybrid navigation solution, we have evaluated the merits of using observations from LEO satellites. The novelty of this paper is in leveraging benefits of LEO constellation in combination with NavIC to improve availability, DOP, and accuracy, especially under partial visibility conditions.

Moon research is closely related to space exploration, with research stations being deployed on its surface for long-term. An essential element in this context is the provision of a soft landing system which is highly accurate and reliable. This paper aims to develop a relative terrain based navigation system using computer vision techniques to aid in accurate soft-landing. High-quality surface images can now be obtained at all stages of landing using modern computer vision systems, and they can be processed in real-time. The viability of using computer vision techniques is demonstrated using a lunar lander simulator developed in-house.

Pulsar Navigation is the future pathway for achieving autonomous navigation in deep space missions with uniform accuracy. The position accuracy possible to achieve by this technique is always the topic of debate. Study of efficient unbiased Phase estimation algorithms with its error bound limit is essential for navigation. This article focuses on how Pulsar timing profile impacts position accuracy via phase estimation. It models different Pulsars with varying X-ray photon flux and profiles' shape and studies position error by statistical simulation of photon event data. It proposes the selection criteria of Pulsars for navigation with predicted accuracy.

Surface exploration and data collection by planetary rovers are challenging due to unknown complex planet terrains. This paper focuses on developing a Deep Reinforcement Learning (DRL)-based controller for rovers to enable safe operation. The necessary control input for safe and efficient vehicle maneuver is derived using the Control Barrier Function (CBF)-based safety protocols. Deep Deterministic Policy Gradient (DDPG) algorithm is used as a DRL framework to find the optimal exploration policies for the rover. Numerical simulations on different vehicle models show the efficacy of the proposed safety method for planetary rovers.

Navigation with Indian Constellation (NavIC), also called as Indian Regional Navigation Satellite System (IRNSS), is a satellite-based navigation system developed by the Indian Space Research Organization (ISRO). A new NavIC satellite (NVS-01) was launched, which transmits a signal in the L1 band, and adopts Synthesized Binary Offset Carrier (SBOC) modulation. This paper presents the characteristics and experimental results of the acquisition and tracking of L1 SPS signal, transmitted by NVS-01. MATLAB is used to perform the acquisition and tracking. This work is useful to NavIC research community for developing NavIC L1 receivers.

Global Navigation Satellite System Interferometric Reflectometry (GNSS-IR) is commonly employed to extract information about the vicinity around an antenna. Within the GNSS-IR domain, Navigation with Indian Constellation Interferometric Reflectometry (NavIC-IR) represents a recent addition. This research paper delineates the fundamental principles and methodologies for creating a standalone software application that preprocesses and estimates the amplitude of NavIC multipath signals to gauge soil moisture content. The primary objective of this research is to disseminate the software within the technical community, aiding users in NavIC-IR analysis using navigational satellite signals.

One of the important elements in Human spaceflight is the technology required to enable humans to interact, monitor and control various onboard systems and provide them with essential information. To cater to this requirement for the Gaganyaan mission, a Crew Interface and Display System (CIDS) system based on an embedded SoC (System on Chip) has been developed at SAC/ISRO. This paper elaborates the key features, hardware-software architecture, environmental characterization and test results of the realized CIDS. This compact, reliable and versatile system weighs approximately 2.0 Kgs and dissipates less than 15 watts of power under nominal conditions.

Gaganyaan program represents India's inaugural endeavour to establish human presence in Earth's Low Earth Orbit. The Orbital module is designed to accommodate astronauts and various electronic systems like environment monitoring systems, crew display systems, cabin lighting systems, camera systems, communication systems, audio-video processing systems, etc. Crew Cabin Systems Controller (CCSC) Module is an integral part of Audio Video Processing System that serves as a crucial intermediary between on-board electronics and Mission Computers for Tele-Command & Telemetry information exchange. This paper offers a comprehensive exploration of the design of Fault Tolerant Crew Cabin Systems Controller for the Gaganyaan mission.

On-orbit manual attitude control of manned spacecraft is accomplished using external visual references. National Aeronautics and Space Administration (NASA) spacecraft permit an aircraft windshield type "front view", wherein an arc of the Earth's horizon is visible to the crew in de-orbit attitude. Russian and Chinese spacecraft permit the crew a "bottom view" wherein the entire circular Earth horizon disk is visible to the crew in de-orbit attitude. Our study compared these two types of external views for efficiency in achievement of de-orbit attitude. Results from our study can be used for design of manual on-orbit attitude control of manned spacecrafts.

The focus of the paper lies on creating a simulator for free floating (no external forces or torques; in free space) spacecraft manipulator systems (robotic arm mounted on a spacecraft) in MATLAB. Spacecraft manipulator geometry for which simulator is made consists of a base-spacecraft, manipulator links, revolute joints and end-effector. The simulator can handle various masses, Moment of Inertia, DH parameters, variable number of links and joints, etc. The simulator works on the Lagrangian approach and was independently validated against MuJoCo, an open source physics simulator for multi-body dynamics with contact.

In this paper, the design and characterization of the thruster system for a 3 degrees of freedom (DOF) spacecraft simulator is presented. Ground based friction-free, low-gravity Hardware-In-the-Loop (HIL) simulators provide an safe and efficient way of validating control algorithms for spacecraft operations. To design test platforms that can emulate cubesat-like dynamics, high-speed blowers are used to provide thrust in the system. It has significant impact on reducing the weight, size and the cost of the simulator. This paper presents a comprehensive analysis of the thruster system, including its design, performance characteristics, and numerical modeling with validation of thruster performance.

In this paper, design and evaluation of two variants of early fire detector for human space capsule is presented. Presence of electric spark or smoke is considered as an early indication for fire. The proposed system is capable of detecting smoke comprising of volatile organic compounds (VOCs) produced due to overheating of materials used on board and can detect an electric spark as well as fire. Experiments were carried out by overheating and burning six materials recommended by ISRO for assessing the performance of proposed system. The proposed work is an outcome from collaboration with SAC ISRO, under RESPOND program.

High power THz BWOs are being investigated for communication, defence, space, bio sensing, spectroscopy, etc. The RF SWS is the most critical component for a high power BWO because it primarily decides the efficiency, tuning range, and spectral purity of a BWO. Analytical design tools are developed for designing RF-SWS and determining cold and hot RF performance of a BWO. The design of SWS and RF performance of various published THz BWOs, are evaluated using analytical design tools and compared with the published results of different BWOs. The comparative results for a 110mW, 1THz BWO are presented in this paper.

Ceramic Matric Composites are the most promising candidates for high-temperature applications in space and defense industries. However, the strength of these composites is dependent on the porosity, and hence, the study of change in porosity with high-temperature exposure is crucial. Here, THz-time domain spectroscopy has been adopted in reflection mode to extract the porosity of the composite samples. Further, the nondestructive testing capabilities in terms of identification of different types of defects, namely delamination and induced crack, have been performed using the THz continuous wave imaging system, with distinct contrast delineating the areas of defect in the acquired images.

Terahertz (THz) imaging, operating between 0.1-10 THz, offers promising potential for security screening due to its unique properties. THz radiation due to its low photon energy makes it safe for biological materials, while its smaller wavelength compared to millimeter waves enables higher resolution. A THz Package Scanner using 0.1 THz as source and a line detector has been realized. This scanner has a capability to scan small packets for detection of hidden objects such as knife, blade, scissors etc concealed under small packets made up of paper, plastic, wood. Additionally, it offers the potential for spectroscopic analysis and metal detection.

Characterization of mm-wave Antenna Feed Systems is fundamental and essential requirement for design and performance evaluation of any system. Far Field test range provide the required information in less time with less mathematical complexities. Intermediate Frequency based Antenna measurement system presented that allows to characterize the antenna feed systems from 140 to 220GHz using frequency extenders. This requires different stages of RF multipliers, Solid State Amplifiers to generate frequencies beyond 40GHz/67GHz. In this paper systematic design, development and demonstration of Far Field antenna measurement system at WR5 (140GHz-220GHz) frequency band is presented including the measured performance of Pyramidal Horn Antenna.

This work presents a near-unity narrowband metasurface absorber (MSA) with an absorptivity (A(f)) of 99.1% at 4.74 THz. The MSA covers a spectrum from 4.68 to 4.8 THz (2.53%) with an A(f)≥90%. DC biasing of graphene sheets leads to excellent tunability from 2.7 to 6 THz (3.3 THz). The narrowband A(f) over a wide THz range helps suppress electromagnetic interference in the desired band. The MSA is polarization-insensitive and works well for wide-incidence angles. The metasurface is compact and ultra-thin, making it a suitable candidate for smart THz applications.

A Geared Rotary Actuator(GRA) is a mechanical assembly that is used in aerospace industry for providing controlled motion to secondary flight controlled surfaces. These actuators are used as powered hinges for aircraft structural movements operating against aerodynamic loads for different aircraft manoeuvres. The internal mechanism of a GRA consists of a compound planetary gearbox or an epicyclic gear train. This paper describes the various configurations possible and selection of suitable configuration for epicyclic gear train of a Geared Rotary Actuator.

This work entails the development of an end-to-end communication system workflow through integration of Keysight SystemVue, Ansys HFSS, and Ansys STK tools. Utilizing Model-Based Systems Engineering (MBSE), we implemented user requirements, Swap-C constraints to determine the architecture and conduct trade studies for DBF (Digital Beamforming) systems. SystemVue facilitates detailed DBF RF system modeling and optimizes performance through vendor model integration. HFSS enables high-fidelity beamforming analysis by incorporating a phased array onto a satellite platform. STK validates mission dynamics, manages satellite measurements(6DOF), and oversees the Link-budget with ground stations. Furthermore, STK integrates channel extraction into SystemVue to dynamically verify system performance.

Manned-ISR is the capability to carry out surveillance reconnaissance and Intelligence using manned-aircraft. The Manned-ISR mission include gathering information day-night from standoff-ranges and has the capability of on-board analysis of gathered intelligence. Further, Manned-ISR mission transfers gathered intelligence to other airborne platforms and ground control stations through Operational Datalink, SATCOM datalink and wideband Line of sight (LOS) datalink to exploit the data collected from a mission. An ISR-system essentially includes sensors (EO/IR, SAR/GMTI, and SIGINT) which provides raw data, Intelligence Exploitation System for generation of information, common operating picture, and networks for disseminating processed information to intended users.

Though Model based System Engineering (MBSE) for complex products has manifold advantages, there is a need to find techniques to facilitate its adoption. Here, we discuss ML technique based on Generative AI particularly Natural Language Processing (NLP) and propose its integration with existing MBSE tools. The conceptual framework of generating requirements from unstructured documents using NLP is presented. The same technique to be utilized for generating Systems Modeling Language (SysML) model entities by training NLP model with labelled data. Once the model is trained and integrated with SysML tool, it eases applying MBSE for multi-domain multidisciplinary complex systems.

Mission System Integration Rig (MSyIR) setup facilitates the integration, testing, evaluation of Mission payloads of Airborne Surveillance system prior to actual flight test in a controlled environment. In MSyIR, the sensors part of Aircraft surveillance platform can be seamlessly integrated and tested either as actual or simulated. The test setup can use functionally simulated sensor model for all the sensors in the absence of actual sensor.
This paper elaborates the framework for a centralized simulation controller that manages multiple airborne sensor simulators in a cohesive manner to perform mission simulation.

Retrading Field Energy Analysers (RFEA) are generally used to measure ion energy distribution in high energy ion beams. In this paper, we present a two-grid RFEA that was designed specifically for measuring distribution of low energy ions in glow discharge. Selectivity of low energy ions was ensured by placing the grids as close as 100 µm and by using a picoammeter for measurement. Simulations were run to identify grid transmittance and dimensions. The actual RFEA was fabricated using 200 µm thick stainless steel grids. The number density, energy distribution of ions, and plasma potential were calculated from the RFEA signal.

The electromagnetic compatibility (EMC) is an important issue for wearable devices due to their proximity to the human body and the potential for interference with other wearable/non-wearable electronic devices lying in the vicinity. The role of artificial magnetic surfaces (AMC) in achieving the EMC is investigated in this paper. The wearable RFID tag placed over a foam substrate is mounted on the proposed AMC structure. A detailed parametric study to investigate the effect of the dimension of the AMC ground plane is carried out which plays an important role in enhancing the directivity and F/B ratio.

This paper discusses strategies for addressing Error Vector Magnitude (EVM) issues in a Digital System (DS) during the Radiated Susceptibility Test (RS103). The DS, part of a Software Defined Radio (SDR) system, is crucial for signal processing, operating at High operating frequency. During testing, it was found that the DS's EVM are poor against the specifications under in band frequency E-field radiation at 5 volts per meter. The paper outlines how susceptible areas were identified and mitigation strategies were implemented to resolve these issues effectively.

The authors present a mode converting antenna using step waveguide discontinuities at 3 GHz. The step waveguide discontinuities are introduced in one half of the circular waveguide for the mode conversion (TM 01 to TE 11 ). The converted mode is radiated from a circular horn antenna which has an aperture radius of 1.5λ. The total length of the mode converting antenna is 2.5λ. The maximum radiation of antenna at the boresight exhibits a gain of 12.6 dBi, sidelobe level of less than 20 dB, bandwidth of 290 MHz (9.6%) and a return loss of 17 dB at 3 GHz.

In spacecraft operations, ensuring the spacecraft health is paramount for mission success and longevity. The health analysis involves meticulous examination of data, typically presented in the form of graphs and plots. This process demands substantial human effort and time investment, where analysts determine the spacecraft's condition based on patterns observed in related parameters. However, this manual approach can be significantly enhanced through the integration of AIML algorithms. Here propose a novel framework for automated health analysis of spacecraft utilizing AIML techniques. By harnessing the power of artificial intelligence, our system aims to accelerate and streamline the spacecraft health assessment process.

Object detection in airborne surveillance is constrained by low size, weight and power. Under these constraints, detection speeds can be improved using a Region of Interest (ROI) based approach. This paper outlines an ROI-based detection utilizing the You Only Look Once (YOLO) model, augmented with mouse interaction and polygon area functions. Mouse interaction enables user-driven selection of ROIs for concentrating on specific regions of interest. Additionally, polygon area function facilitates the creation of irregularly shaped ROIs, for object tracking. Our experimental findings illustrate the efficacy of the suggested approach in achieving accurate ROI detection while maintaining the real-time performance.

This paper presents a new method of a faster and precise thermal control in space with an emphasis on the need of real-time prediction in dynamic environments. The total irradiation on sun sensors is computed by considering different environmental factors as well as satellite dynamics within the proposed approach. A neural network-based model is trained on this data, which is then coupled with the control system of the satellite for quick thermal adjustment. Successful validation lays the foundation for utilizing simulation-based physics-informed thermal analysis in conjunction with machine learning to influence the control system in near real-time for satellite sub-systems.

In this work, aerodynamic design optimization of a slender body aerospace vehicle has been carried out through an automated computational fluid dynamics workflow and shape optimization using state-of-the-art machine learning techniques. A total of 19 design variables are considered in the workflow, and 113 candidate designs were explored to cater to the overall design space. Non-linear response surface models have been evolved for each of the output variables and the root mean squared error is reduced over several iterations. Aerodynamic efficiency improvement of 4% to 14% has been achieved based on various design constraints on the candidate ‘optimized' aerodynamic design.

Anomaly detection plays key role in spacecraft operations. One way of classifying anomalies is to find deviation in parameter trend by comparing it with previous data. This study aims to find such anomalies by using distance metrics like Euclidean, Cosine and using isolation forest to find out outliers in the data. Application of this method has been verified using temperature sensor data of spacecraft. To evaluate the model, outputs generated were verified with known anomalous observations and manual analysis was done for other observations. The results obtained are promising with high detection and low false alarm rates.

In this paper, we present a joint convolutional neural network and gated recurrent unit based deep leaning model for recognition of modulation schemes in blind RF environment. The raw I/Q samples from RadioML2016.10b dataset are used as the input data. The proposed model offers significantly improved accuracy of the modulation schemes at the low SNR region ranging from -2 dB value to 4 dB. Through numerical results, it is shown that the proposed model yields recognition accuracy upto 99% at 0 dB SNR. The average accuracy achieved is 93.3%, which is a significant improvement in the recognition performance.

This paper discusses development of a technique to obtain smoothed airdata during wake penetrations and atmospheric disturbances encountered by a high-performance aircraft. The technique uses MIL grade rate and acceleration sensors and airdata sensors within the Digital Flight Control Computer. The paper includes a novel method of estimating inertial velocities from 3 axis linear accelerations without any dependence on GPS, which can be used for filtering out wake effects, gusts and turbulence effects on airdata sensors, while retaining good bandwidth. The technique has been extensively evaluated using flight test data of a high-performance aircraft and it has yielded promising results.

A Flush Air Data System (FADS) comprises of an array of ports infused on a flying body that measures the surface pressure. From these measured pressures, free stream airdata parameters such as static pressure, true air speed, angle of attack and angle of side slip are then computed. One of the major difficulties of a FADS is the design of the computational algorithm. In this paper, a fusion of flush ports with inertial sensors is carried out to compute the airdata parameters.

NAL has developed a sub-scale version of HAP for low-altitude flight. Operating subscale HAP is more susceptible to atmospheric disturbances and wind variations at low speed-altitude. Therefore, prior to the flight test using COTS, it is essential to assess the aircraft's performance with different control modes in a simulation environment. This paper provides detail on developing a SILS setup comprising a flight dynamic model integrated with the ArduPilot, GCS interface and panoramic visualization software.

This work proposes a novel pipeline for collaborative task completion using a heterogeneous swarm consisting of an Unmanned Aerial Vehicle (UAV) and a Unmanned Ground Vehicle (UGV). The system leverages the strengths of each platform: a UAV's rapid, wide-area scanning capabilities and a UGV's dexterity, extended operation time, and payload capacity. This collaboration addresses limitations in traditional single-platform approaches. The pipeline is demonstrated in a simulated environment using ROS2 and Gazebo. The UAV scans the area of interest from which objects of interest are detected on UGV. The UGV is further tasked to explore the detected areas of interest.

Achieving velocity vector roll is a critical requirement in advanced aircraft control design. This paper utilizes Differential PI scheme as baseline controller, where lateral-directional and longitudinal controllers are designed in stability and body axes, respectively. Since linear aircraft models are used for control design, the controller fails to achieve design performances when used in nonlinear Six-DoF aircraft dynamics. Hence, a compensation strategy is presented to achieve the desired performance. Due to the multi-axis control design, compensation terms appear in different aircraft frames, requiring extreme care in their implementation. The efficacy of the proposed scheme is shown through comprehensive simulations.

In automation and robotics for space missions, computations are executed using finite-length hardware. This paper focuses on establishing stability criteria for two-dimensional discrete systems with delays and finite word-length implementation. Two stability criteria are proposed. The first criterion considers the combined impact of these factors, while the second criterion accounts for saturation overflow nonlinearities and delays. The utilization of Wirtinger-based inequality and reciprocally convex approaches has been done to obtain these criteria. Through illustrative examples, the practical significance of the results is demonstrated.

Targets are imperative for validation of any weapon system. Targets in the form of Unmanned Aerial Vehicles (UAV), Ground models in stationary and moving platforms are generally used to simulate various (Radio Frequency) RF and (Infrared) IR environments for gunnery training. This paper presents design and development of a passive RF target for evaluation of various weapon systems and elaborates design methodology of a stable buoy with structure for mounting user payload which is deployed in sea for sea state five.

A novel edge spiral substrate integrated waveguide (SIW) antenna design is presented in this paper. The spiral arms of antenna are placed at the top plane. The antenna is fed through small strip at the centre of SIW cavity and in between two symmetrical spiral arms which shows state of the art. The spiral antenna at top and its complementary design at the bottom ground plane is resonating at 14 GHz (13.56 GHz-14.54 GHz). The proposed design shows wide bandwidth of 980 MHz due to the two spiral arms of antenna.

This work proposes a wideband high-gain substrate integrated waveguide (SIW) antenna array for sixth-generation (6G) applications. The proposed SIW-based 2 × 8 antenna array, designed at W-band, comprises half-bowtie-shaped slots with two triangular-shaped patches in each half-bowtie-shaped slot etched for feeding the slotted circular radiating patches present at the top layer. The antenna achieves a bandwidth of 2.66% (92.7-95.2 GHz) while maintaining good radiation patterns and total efficiency throughout the operational band. Notably, it exhibits a gain of approximately 20 dBi and a total efficiency of 85.1%.

The ultra-wide band operation and wide-angle scanning related features of the Vivaldi antenna make it a preferable choice for Electronic Warfare systems. For stealth platforms, designing an efficient Vivaldi antenna poses an additional challenge. The RCS of the Vivaldi antenna can be reduced in broadside/end-fire direction by removing the metal portion of the antenna. The main challenge is to maintain the antenna gain and VSWR with reduced RCS over its wideband operating frequency range. This paper presents a novel EM design of Vivaldi antenna having VSWR (<2.5), and gain (10 dBi) with monostatic/bistatic RCS reduction of 6 dB.

A wideband Metal Type Vivaldi antenna array designed at L-band is elucidated in this paper. Metal Vivaldi antennas provide better performance in terms of bandwidth and radiation efficiency due to their robust construction and higher conductivity compared to PCB's. They can withstand higher power levels without suffering from degradation in performance. In this paper, the antenna array consists of 40 Vivaldi elements placed at a distance of 0.5 lambda. The proposed antenna array is simulated at 1.3GHz frequency. The simulated array results show that the VSWR is less than 1.4 and gain of 5.5dB.

In electronic warfare (EW) and interferometric applications, spiral antennas are preferred. In this paper, a right-handed circularly polarized (RHCP) cavity-backed Archimedean spiral antenna has been designed for operating frequency range of 2-18 GHz. The antenna feed consists of an optimized balun structure and is backed by a metallic cavity of frustum shape. An EM absorber-based ring has been used to reduce back-lobes and hence enhance the antenna gain. It is shown that the VSWR of the designed spiral antenna is below 2.2, gain >4 dBi and the axial ratio is less than 3 dB over 2-18 GHz.

This article introduces a miniaturized antenna for 5G-II band millimeter-wave communication. The antenna's comprehensive simulations carried out using CST Studio, employing an FR-4 substrate with dimensions measuring 10 × 12 × 1.5 millimeter cube. The proposed design exhibits exceptional qualities, featuring an impressive impedance bandwidth of 166% The operational frequency range of this antenna extends from 9.1 GHz to 100 GHz, featuring a central frequency of 45.45 GHz, positioning it effectively within the 5G-II Band. The antenna consistently maintains polar patterns and efficient performance. It showcases a substantial gain of 5.85 dBi and an impressive efficiency rating of 89.2%.

This paper describes the Design of Ka Band Hemispherical Dielectric Lens and Horn Assembly for Discrete Beamforming. In a Phased array antenna, the challenges in beam forming include high cost, complex architecture and expensive phase shifters. In this paper, an antenna consisting of horn and hemispherical lens assembly is proposed that can achieve beam agility and configurability in beamforming based on feed locations. The design of the antenna is carried out in HFSS, and various parameters such as return loss, directivity are optimized. An improvement of 11 dB in directivity is observed with the designed hemispherical lens.

This article discusses the design of a split ring resonator (SRR) for stealth application in EW(Electronic Warfare). The SRR with conducting block added in between parallel plates is designed incorporate some capacitive effect. The proposed SRR resonates at 6.9 GHz and the bandwidth of the resonator is 2.83 GHz. It is operated in C-Band. It gives the reduced RCS with respect to reference antenna of 24 dBsm over the 5 to 10 GHz frequency range. The effect of width variation on refractive index has also been analysed.

This paper presents S-band wideband evanescent mode waveguide bandpass filter for spacecraft testing applica- tions. Most of the evanescent filters in S-Band are used with narrow bandwidth of less than 5 percent fractional bandwidth to the centre frequency, however in this paper design and realization of an evanescent mode waveguide filter with wide bandwidth greater than 15 percent is attempted and presented. In this paper evanescent mode waveguide filters are used for achieving the above desired parameters. These filters can achieve considerable size and weight reduction with excellent out of band rejection performance compared with other waveguide filters.

This paper presents an improved clutter removal technique using comb-notch FIR filter. In conventional nonrecursive and recursive clutter removal approach, the range profile could not be detected in presence of strong clutter response while target is slowly moving. This approach is capable to remove clutter responses with a 20 dB improvement factor. The experimental data is recorded for indoor and outdoor environment using S-band FMCW radar and the proposed clutter removal technique is applied. According to the experimental validation, this technique is more capable to remove clutter responses while adequately preserve the signal coming from moving target.

The paper utilizes coupling matrix approach for design and simulation of 8 th order cavity bandpass filter in CST Microwave Studio. The bandwidth and center frequency of the filter was tuned for desired frequency band using coupling and tuning screws. For design verification, the filter has been realized using aluminum alloy material. The filter has been realized in a compact form factor. Rejection of order of -98dB at 300 MHz away from center frequency with insertion loss of less than 0.6 dB at center frequency has been achieved.

This paper describes about design and analysis of miniaturized bandpass filter with broad stopband for Global Positioning System (GPS) space application. A bandpass filter with five transmission zeros has been realized through the investigation of a unique symmetrically loaded shunt coupled line with pair stepped impedance stubs. Using even odd mode analysis, the transmission zeros frequencies of the filter response have been verified theoretically. The proposed filter compact size and wide 3dB fractional bandwidth of 57.8% covering the frequency 0.75 to 1.36 GHz. Designed bandpass filter may be useful for GSM 900 MHz, GPS L2 and L5 band application.

This work presents a new wide stop band diplexer for S and C band. The parallel coupled line sections with an additional microstrip line section is used for each pass band path. The mathematical analysis with generalized guideline is presented for diplexer design. According to the measured results, the stop-band rejection is achieved up to 10fc1 while maintaining 20dB suppression and 2.16 pass band frequency ratio. The in-band isolation between two output path are below 43dB, 56dB; insertion losses (IL) are 1.86dB, 2.2dB; and bandwidths are 30%, 28% at lower and upper pass band path of the diplexer respectively.

A novel microwave NDT dielectric loaded cavity resonator sensor is presented for accurate measurement of coating thickness on CFRP. With this technique, resonance frequency may be used to determine CFRP coating thickness directly. To enable TM110 mode electric coupling, the circular ring aperture acts as a coupling element between the CFRP coatings and the cylindrical dielectric-loaded cavity. The electromagnetic simulation, and experimental measurements demonstrates a high level of agreement. This methodology provides a highly efficient for on-site evaluation of coatings thickness on composite aircraft structures and other relevant applications.

This article demonstrates design workflow for an S-band coaxial cavity duplexer. The two 50 MHz channels of the duplexer operate within 2-2.05 GHz and 2.1-2.15 GHz. The channels are synthesized with SynMatrix and tuned using its AI based intelligent tuning feature, which seamlessly connects with HFSS for optimization. Validation of the power handling capability of the duplexer in space environment is done in HFSS with multipaction analysis. The results obtained provide significant information about power handling capability of each channel, facilitating steps to mitigate the power breakdown.

The advanced communication satellite transmitter systems are designed with complex redundancy configuration for achieving fault tolerance, resource sharing and high reliability. The reliability prediction of such systems with shared elements and redundancy, using conventional method of modelling, is not accurate. This is because of the fact that the impact of failure of the independent element or shared element will be different on the system. This paper brings out the methodology for reliability modelling of such complex systems using Continuous Time Markov Chain approach and discusses reliability modelling of an 8:10 cold standby dual TWTA transmitter system of a communication satellite.

Increasing micro-miniaturisation is driving decrease in volume of electronic packages, putting stringent demand on use of cutting-edge ultra-high density I/O devices in smaller real estate on PCBs. This has put emphasis on PCB technologies like HDI that uses micro-vias as interconnects. It employs sequential build, unlike conventional MLBs, with blind & buried micro-vias on the outer-most layers along with buried vias in inner-layers. This in-turn provides increased circuit density in the PCB and are compatible with the latest high-density IC packaging technologies. This paper covers critical quality evaluation methodology to assess the space worthiness of HDI technology and its outcomes.

The flight software size is increasing to take care of safety and security parameters, autonomy features and also to handle contingencies like failure detection, isolation and recovery. The growth rate of software will increase for future missions as new functionally gets added in software rather than hardware. This paper mainly concentrates on the software complexity metrics based on the static analysis carried out. This analysis helps to address the risks associated with development in size and complexity of flight software.

Airborne Early Warning and Control (AEW&C) systems development is a multi-disciplinary activity. Centre for AirBorne Systems(CABS) has indigenously designed, developed and integrated the Mission Systems(MS) on EMB-145 platform. Airworthiness of the MS is ensured by following procedures and meeting clearly defined technical requirements stated by the user, the Indian Air Force (IAF). Organized airworthiness quality assurance practices from the programme inception till the induction and continued airworthiness has led three AEW&C aircraft delivery to IAF. The multifaceted role of Quality Assurance and challenges in the journey of airworthiness certification of MS hardware is presented in this paper

Reliability Modeling plays a crucial role in ensuring seamless operation of complex satellite data reception system to ensure consistent performance for longer periods. This paper presents a novel approach for the same using a case study on one of the antenna systems and its validation using field data. It also provides a framework to understand the effect on performance of the system in case of any up gradations or new designs of the unit. It estimates the duration for which the system can operate continuously for desired level of 3-sigma reliability which is vital input to maintenance plan.

The present paper attempts to find optimal locations of aircraft antennas on board a commuter aircraft using the NSGA II algorithm. The NSGA II Pareto optimal solutions provide a tradeoff between the two objectives of coupling and radiation pattern coverage unlike a single weighted objective that scalarizes the objectives into a single cost function and has limitations to weight selection sensitivities and lack of information of the tradeoffs that can be made. The present method also has advantages of speed and minimal computational resources to provide an optimal solution. Antennas on both sides of the fuselage are considered for analysis.

Airborne early warning and control systems are complex system of systems performing varied functionalities to achieve emergent mission objectives, with high reliability and performance requirements. For these systems, to manage complexity and to meet stringent timelines, system engineering processes are adopted. At the same time the organization would like to adhere to aerospace standard AS9100D Quality Management system(QMS). In the scenario, it is imperative to have an Integrated QMS (IQMS) to ensure quality and customer satisfaction at the same time. This paper brings out alignment of SE processes with AS9100D to bring out IQMS for organizations developing avionics systems.

Traditional ground support software has often been suffering from inefficiencies, limited scalability, and high costs. This paper describes new generation software applications like web-based centralized monitoring and control software, Multiranger ranging which facilitates simultaneous multi-spacecraft ranging along with Semi-Active mode of ranging which caters to overcome above drawbacks and is built and improved over years of operational experience. This paper shows the pivotal role of software in revolutionizing space operations, focusing on its impact on ground-based support systems.

The global space age sees increased use of polar orbits for Earth observation, exploration, and communication. A ground station facilitates telecommunication with spacecraft and reception of radio waves. It comprises a reception antenna, downlink and uplink chains. Telemetry (TM) and Telecommand (TC) form the primary information stream. This paper explores the strategic importance of polar ground stations, emphasizing their unique roles. It aims to overview available ISRO's polar ground stations, historical trends, and development of telemetry, tracking, and command (TTC) systems. The paper highlights the growing significance of polar ground stations and discusses future advancements and commercialization aspects.

Satellite ground system is an essential element to support the satellite operations during the different phases of its mission. The baseband system in the ground segment plays a key role by performing Tele-commanding, Ranging, and Telemetry processing. The increasing fleet of satellites requires the handling of many ground system elements altogether. Virtualization techniques and Automation can be combined to enhance resource utilization and contingency handling. This paper explores the Baseband Monitoring and Control Software (BMCS) developed to automate ground system in a satellite control facility by utilizing the virtualization and monitoring and controlling of Baseband systems.

This paper discusses about the Multiple Co-located Satellite's Telemetry reception, Commanding & Ranging operation in Ku band Frequencies through single Ku band Antenna. In the proposed solution Ku band Antenna will be tracking to mean angles of all the co-located satellites to minimize the signal variation over a day, also power amplifier operating point is optimized to meet IMP requirement.

Multi Object Tracking Radar (MOTR) is an Active Phased Array Radar designed to track multiple objects with electronic beam steering capability. During launch vehicle missions, MOTR is used for tracking intended targets viz. on-going launch vehicle, spent stages, boosters, burnt-out stages etc. Time shared scanning is also carried out to detect the presence of any other target. Analysis of the detections from scan beams indicate the presence of considerable debris ejected from solid propellant stages of launch vehicle. This paper deals with estimation of ESD derived from RCS of detections and gives statistical estimate of size of ejecta.

This paper underscores the criticality of precise orbit determination for successful spacecraft missions, especially in deep space endeavors. By examining Doppler data from both open-loop receivers and TTCPs in the Chandrayaan-2 mission, it highlights the superior capabilities of the former in capturing finer residual Doppler. The findings stress the significance of advanced measurement techniques, essential for enhancing orbit knowledge and enabling crucial studies in deep space, such as radio occultation and solar corona investigations. Ultimately, this research contributes significantly to advancing the precision and reliability of spacecraft operations in the challenging realm of deep space exploration, underscoring its pivotal importance.

The Space Link Extension (SLE), a CCSDS protocol, specifies a common interface between space agencies, to exchange satellite telemetry, telecommand and science data. ISTRAC (unit under ISRO), already provides cross support over SLE for TTC services. The existing SLE architecture is more suitable for TTC data transfer services for external missions with Provider and User Components. ISTRAC has recently implemented Return Channel Frame (RCF) service, for science data provisioning to end users. Considering the higher data rate, and also the need of secure internal architecture within ISTRAC, a new architectural design is implemented and presented along with the challenges encountered.

The ground segment is equally vital, alongside the space segment, in managing pre- and post-launch activities to meet the requirements of the remote sensing user community. Managing the day-to-day operations related to data product generation involves navigating numerous operational challenges. These challenges include tasks such as data transfer, error analysis and reporting, mapping out comprehensive details of daily payload planning etc., By leveraging existing advanced technologies, the development of automation utilities can relieve the operations team from undertaking mundane tasks. This paper describes the various automation modalities implemented in the data production chain to swift and enhance problem resolution.

This paper presents the design and development of miniaturized reconfigurable frequency synthesizer module for frequency generation. The proposed FS module is based on indirect frequency synthesis technique and uses PLL chip for generation of two independent coherent signals at 750MHz and 4800MHz. To achieve low phase noise, temperature-controlled crystal oscillator is used as reference and PLL output is reconfigurable based on requirement. The miniaturized FS generic module is realized on multilayer FR4 board with available commercial off the shelf components in size of 86mmx88mmx1.6mm. The desired performance of module is also achieved over -15°C to +55 °C temperature range.

One of the major advantages of onboard Digital Beam Forming (DBF) system is that it substantially reduces the SAR sensor data rate, while improving the system performance. ISRO's first 24-channel Data Acquisition and Beam Forming (DABF) system has been successfully designed and developed at Space Applications Centre for Dual Frequency Sweep SAR (Synthetic Aperture Radar) mission. This paper discusses the hardware design details, beam forming algorithm implementation and performance of multi-channel data acquisition & digital beam forming system, developed for the NASA-ISRO Synthetic Aperture Radar (NISAR) mission, based on a novel Sweep SAR concept.

NovaSAR is an S-Band SAR built by Surrey Satellite Technology Limited (SSTL), UK, in collaboration with AirBus and launched by ISRO in 2018.It operates in the frequency band of 3.1-3.3 GHz and provides medium resolution data in Stripmap and ScanSAR imaging. The ground resolutions varying between 6m-45 m with Single Pol(HH, VV), co-pol Dual Pol(HH & VV), Co-Cross Dual (HH & HV, VV & VH) and Tri Polarization(HH, VV & HV) capability.

Ground Penetrating Radar (GPR) is crucial for non-destructive subsurface investigation. However, it encounters many challenges like signal interference, clutter, complex media characteristics, etc. Advanced signal processing algorithms are essential to overcome these challenges, ensuring accurate identification and differentiation of subsurface targets. In addition to addressing these needs, this paper presents the development of robust GPR software using the MATLAB App Designer tool. The software incorporates data handling, clutter reduction, velocity estimation, and imaging. It also includes classification methodologies for target discernment. This comprehensive approach ensures accurate and reliable results, enhancing the utility of GPR technology for diverse applications.

This article presents a dual-band shared aperture antenna array for ASAR applications, comprising eight elements in Chebyshev configurations for X/Ku-Bands. Achieving a scanning angle of ±25 degrees, it uses 0.7λ inter-element spacing to mitigate mutual coupling and ensure good isolation. The array demonstrates SLL performances > -25 dB and quantified isolation between bands and conditions. Chebyshev synthesis yields SLL values of -26/-24 dB (X-band) and -27/-26.8 dB (Ku-band). Measured gains for Chebyshev synthesis are approximately 16.2/16.5 dBi (Open-Ended), 13.1/14.2 dBi (Short-Ended), and 15.3/15.2 dBi (Load-Ended) across X/Ku-Bands. Impedance bandwidth is wide, at 100 MHz (X-Band) and 230 MHz (Ku-Band).

Landmines pose a significant challenge to military operations and civilian safety. Traditional Ground-Penetrating Radar (GPR) systems struggle to identify contemporary plastic landmines due to their low reflectivity and similarity to benign objects. This research pioneers the integration of You Only Look Once version 8 (YOLOv8) object classification algorithm with GPR B-scan images, demonstrating notable advancements in subsurface object classification accuracy. By enhancing landmine detection, this study aims to bolster the safety and operational efficiency of the Indian Army in mine-contaminated terrains.

Rapidly increasing fields in application of RADARs place various lateral dimensional constraints on the antenna design that require gain enhancement without tailoring the antenna size. This paper presents design of 1×4 Rectangular Microstrip Patch Antenna Array (RMPAA) both in the presence and absence of Rectangular Dielectric Resonators (RDRs). The radial field analysis of 1X4 RMPAA with two varying lengths of RDRs is detailed. The optimized RDR increases the gain around 2.5 dBi. The designed structure is fabricated and measured in anechoic chamber. The measured results are in good agreement with the simulations performed in Ansys HFSS.

Millimeter-Wave FMCW radar offers highresolution imaging and object detection capabilities, making it ideal for various applications including automotive radar, industrial sensing, security systems, and Imaging. This work presents the modeling of mmWave FMCW radar system for 2D SAR imaging for different objects like square, rectangle, triangle, and circle. The main objective is to reconstruct the object shapes with high resolution by developing numerical analysis. Utilizing MATLAB, the system is modeled and analyzed to achieve high-resolution imaging. The results show good prospects for the use of mmWave FMCW radar systems for imaging multiple objects with different shapes for SAR imaging.

Orthogonal Time Frequency Space modulation is an advanced technique in wireless communications, designed to work in Linearly Time-Varying channels. This paper outlines a low-complexity, discrete-time single-input-single-output (SISO) OTFS system implementation. We also detail a block-wise OTFS receiver that utilizes the OTFS transmission matrix structure. The receiver features an iterative approach, integrating a least squares minimum residual-based channel equalizer, a reliability-based symbol detector, and an interference eliminator. This method is designed to quickly converge by leveraging the channel matrix's sparsity, significantly reducing detection errors while maintaining lower complexity. This enhances performance in high mobility dynamic communication environments such as Aircraft communications.

The baseband design for a cellular base-station or a satellite hub requires a channelizer which acts as digital front end of a receiver. Polyphase FFT (PFFT) channelizer structure is a resource intensive approach to perform this functionality. When the sampling rate requirements and channel spacing requirements differ the standard architecture of a PFFT channelizer has to be modified to meet this implementation constraint. For a communication channelizer the requirements of output sampling rate and carrier spacing have an integral relation with the channel symbol rate. The paper proposes a novel simpler and resource efficient architecture for this scenario.

This paper introduces chirp orbital angular momentum (COAM) beams with non-linear azimuthal spiral phase variation, which have a linear spatial frequency variation in the azimuthal plane, similar to chirp signals. This variation contrasts with the constant spatial frequency variation of conventional OAM beams, making COAM beams resistant to spatial frequency distortions during propagation. The paper shows that COAM beams at microwave/millimeter wave frequencies can be generated using uniform circular arrays (UCAs) with antenna element phase excitations that vary as the square of the element number. This could enable robust OAM communications in turbulent propagation conditions.

Solid state power amplifier-based transmitters have become very common and with the advancements of GaN devices the power output from the PA has increased and hence they are being used in most of the RF Systems. This paper presents an S-band RF power transmitter using an 8-way power divider and combiner, filter, circulator, and antenna integrated into a single system. The 8-way corporate power divider is simulated using a full wave MoM solver in MATLAB ® RF PCB Toolbox ™ and Antenna Toolbox ™. An OFDM signal is fed to the transmitter and changes in the waveform are reported.

Transmission Control Protocol (TCP) is a connection oriented and reliable transport protocol. It considers congestion to be the sole reason for any packet loss on the network and accordingly slows down its transmission rate. As a result, the performance of TCP is greatly impacted over wireless links which are quite lossy. This paper introduces a new protocol, that aims at improving the TCP performance over lossy links. The protocol tries to differentiate between the congestion and corruption over the link with the help of receiver. The simulation results establish performance improvements in comparison to TCP Tahoe and TCP New Reno.

Phased Array Antenna (PAA) requires each element's precise amplitude and phase calibration to obtain the desired array pattern. A more practical approach, i.e., OTA calibration, has been recently employed, targeting future SATCOM/5G/mm-wave radio scenarios. Two well-known methods, mREV and orthogonal coding, are used for PAA calibration. This paper investigates the robustness of the performance of the above techniques in near/far field radiation mode. Experiments are validated on a 1 X 4 L-band uniform linear array. A comparison of the results regarding amplitude/phase tracking accuracy and element failure detection is shown. Calibration errors are explained, and system performance is analyzed.

The correlations obtained can be used as a technique for grouping bands to leverage information from adjacent pixels. High spectral density in hyperspectral images (HSI)s can cause computational complexity. We demonstrate that grouping band information improves generalizations while requiring less computation and strengthens interpolation learning. The bands adjacent to each other display high spectral similarity that is captured by a statistical metric such as correlation matrix. We investigate the impact of combining related spectral bands as a cohesive strategy for efficient interpolation. This addition of detail and texture cannot be ignored because it helps in better resolved images.

A Physics-Informed Neural Network (PINN) has been designed to predict torque control for obstacle- avoiding trajectories and ensure dynamic stability, accounting for the intricate dynamics of these FFSM systems under real- world constraints. The resulting control sequences can be tailored to minimize fuel consumption and ensure safe flight operations, thus improving mission planning and enhancing structural longevity by reducing abrupt movements and mitigating wear and tear. The smoother trajectory, informed by dynamic stability considera- tions, contributes to efficient fuel usage and promotes sustainable space exploration practices.

Machine learning (ML) techniques have been ap- plied for radar applications in recent years. It is still changeling to classify images or objects accurately. This work has modeled 1600 reconstructed object shapes of four different objects like triangles, circles, squares, and rectangles using millimeter-wave (mmWave) FMCW radar principle based on the 2D SAR imaging technique, and the numerical analysis is performed in MATLAB. The Convolution Neural Network (CNN) technique is implemented to perform the objects' classification in a Python environment. The results give a good prospect for the study of ML techniques to classify mmWave FMCW radar data.

The exploration of water ice on the lunar surface is a recent hot topic in planetary science. In particular, the South Pole-Aitken (SPA) region of the Moon is the most promising candidate site and has attracted significant attention. However, most of the previous studies have manually analyzed observation data from limited areas within the SPA region, which is laborious and costly. Therefore, this study aims to automatically generate a geological map of the SPA region by applying multiple clustering methods. The results show that the results of C-Means and Spectral Clustering are close to those of manual analysis.

In this paper, we propose Conv2D-attention based intrusion detection systems (IDS) to secure the network in the industrial internet-of-things (IIoT). For this purpose, convolution on image style input data is applied in the feature extraction section to extract the spatial features. Further, multi-head attention is employed to attend different aspects of input data simultaneously. Furthermore, the feature extraction section is connected to resnet style deep neural networks to provide robust classification. In addition, the softmax classifier is used to predict the label. Our proposed Conv2D attention system performs better as compared to existing system models available in literature.

This paper introduces "rasterMiner," a comprehensive open-source Python software for extracting insights from satellite imagery data. This software offers 30 knowledge discovery algorithms spanning supervised and unsupervised techniques like classification, clustering, pattern mining, image fusion, and imputation. Notable attributes encompass an intuitive GUI for seamless algorithm selection, the adaptability of being accessed as a Python library, and the ability to export findings to standard CSV files for visualization in GIS software. Our software is bolstered by extensive support resources, including user and developer guides and a robust bug-reporting system.

Missile size measurement devices find application across diverse sectors including research-development for designing and verifying prototypes, military bases, and in space exploration. In this project, we achieved significant progress in implementing an instance segmentation pipeline for missiles using YOLO. We collected datasets, preprocessing with annotated images, segmentation masks, training a YOLO model for instance segmentation, performing inference on images to obtain precise segmentation masks for detected missiles. By calculating the pixel area within these masks, we estimated the size of each missile. We evaluated the model's performance using segmentation-specific metrics, ensuring accuracy. Future steps involve fine-tuning, and ongoing monitoring.

For a high-performance aircraft, an accurate aerodynamic model is required for various applications such as flight envelope expansion, high-fidelity ground-based simulators and control laws design. Validation and update of the aerodynamic database of Tejas aircraft were carried out using system Identification techniques applied to flight test data. An incremental model update approach, based on aerodynamic coefficient matching, was used to update the aerodynamic database towards the Final Operational Clearance of LCA Tejas. The updated aerodynamic database was validated by matching the nonlinear simulation predictions with the flight-measured responses. This paper highlights the technologies developed during this process.

This is a circuit for Ultra broadband Power Division / Combining comprising a compact planar structure of microstrip line comprises for line segments of different widths (W1, W2, W3, W4) and Lengths (L1, L2, L3, L4) and with four isolation resistors (R1, R2, R3, R4). In the structure odd segments are mainly for midband frequencies and even segments are mainly for higher side frequencies are cascaded to achieve a ultra-broadband response with reduced no. of discontinuities in a compact size, with less amplitude and phase imbalance. Due to less sections used it gives very low insertion loss.

In this work, authors have presented state of the art development for different band helix TWTs for space applications. In recent years, a number of efforts have been made low gain and high gain helix TWT at CSIR-CEERI for different space applications. Development of such devices involve development, integration and characterization of individual components, namely, electron gun for electron beam generation and confinement, slow-wave structure (SWS) for synchronous beam-wave interaction to estimate power, gain, efficiency and other parameters, collection of spent electron beam from SWS into multi-stage depressed collector (MDC) system.

This paper discusses a GaN-based ultra-wideband high-power amplifier (HPA), low noise amplifier (LNA) and RF SPDT switch. These components are used in transmit-receive modules (TRM). HPAs provide more than10W output power. The LNA, with 30 dBm survivability, has less than 3 dB noise figure across the band. Measurements, done in pulse mode for HPA and CW mode for LNA and SPDT, align well with simulations, showing the HPA delivers 10W, the LNA has 18 dB gain with 3 dB noise figure, and the RF switch has 45 dB isolation with 1 dB insertion loss.

Helix travelling wave tubes are most commonly used as power amplifier for satellite communication. The main objective of packaging of the helix TWT is to protect the integrated TWT from environmental loads. These environment loads are either mechanical vibrations or thermal loads. In this paper author has presented the design of the radiation-cooled packaging of the helix TWT for its space application. The key challenging aspects in the design of the base plate for packaging are axial & radial alignment of the tube, different size of the TWT sub components, high voltage potting at gun and collector side etc.

This paper describes about the utilization of aluminium alloy heat sink fins to dissipate heat effectively in space for thermal management of Travelling Wave Tube Amplifier (TWTA). Anodizing is employed to enhance the low surface emissivity of aluminium fins, but it also increases solar absorptivity, which is undesirable. The objective of the study is to achieve high emissive surface maintaining a favorable ratio of emissivity to solar absorptivity. Through trials and investigations, the study establishes finalized thickness of anodic layer that provides high emissivity and optimum low solar absorptivity which is tested and found suitable for space worthy applications

The Mine Guardian project presents an inventive mine security robot designed to lift laborer wellbeing by giving exhaustive ongoing environmental conditions monitoring and risk discovery capacities inside mining conditions. Containing a modern cluster of sensors and modules, including the DHT11 for temperature and moistness observing, the MQ-2 for smoke identification, and the MQ-7 for carbon monoxide checking, Mine Guardian offers a comprehensive reconnaissance framework for basic natural boundaries. Directed by Arduino controls and furnished with cutting edge deterrent evasion systems driven by a L298N engine driver, the robot moves capably through mines, moderating impact chances and guaranteeing consistent route. Utilizing the NEO-6M GPS module related to Firebase, Mine Guardian conveys exact continuous area following, working with remote observing through Google Guides for upgraded situational mindfulness. Through the Twilio SMS Programming interface, Mine Guardian gives standard updates to mine work force at 30-second spans, enabling them to go with informed choices in regards to mine entrance considering current ecological circumstances. Moreover, the mix of the ThingSpeak IoT stage empowers top to bottom information examination, enabling partners to distinguish long haul patterns and examples in natural boundaries for proactive gamble the executives. Supplementing these capacities, a USB webcam consistently transfers continuous video film of the mine, empowering distant visual review and evaluation of conditions underground. Controlled by the Raspberry Pi 4 processor, Mine Guardian remains as a weighty headway in mine security innovation, ready to rethink wellbeing norms and upset functional practices inside the mining business.

This paper presents an approach to design a 12- element time-modulated asymmetric elliptical antenna array (ATMEAA) for optimum far-field radiation pattern synthesis. By minimizing the sidelobe levels (SLLs), the far-field radiation pattern is designed to minimize the interference of ATMEAA. For achieving the ultra-low SLLs, an optimal combination of switch-ON time sequence and progressive phase delay is determined using meta-heuristic techniques, which are genetic algorithm (GA) and particle swarm optimization (PSO). ATMEAA is also considered for the practical antenna at fundamental frequency 2.4 GHz to calculate sideband levels (SBLs), feed network efficiency, and directivity using the GA and PSO techniques.

In this research work, a drone-based CanSat release mechanism with parachute deployment is designed and implemented. Two methods of deployment are examined: Electrothermal and Electromechanical techniques. Our analysis covers the design and implementation of both models, evaluating their effectiveness, dependability, and suitability for CanSat deployment projects. Our results offer important new information for tiny satellite deployment technology advancement, CanSat deployment mechanisms, and aerial deployment mission success rates.

This paper presents the design and development of a functional Can sized Satellite(CANSAT) prototype focused on acquiring atmospheric data while demonstrating the feasibility

and effectiveness of miniaturized satellite systems. The proto- type incorporates a telemetry system for data collection and

transmission to a ground station, employing reliable wireless

communication protocols for real-time monitoring. Controlled ve- locity descent is achieved through careful parachute dimensioning

and the integration of servo-actuated PID(Proportional-Integral- derivative) controlled fins for precise orientation control. The

successful implementation of this prototype serves as a proof-of- concept for future miniaturized satellite missions, showcasing its

capabilities in telemetry, communication, and controlled descent.

This paper presents the design and development of a digitally twinned 1U CubeSat, representing a significant advancement in satellite technology. The CubeSat is equipped with digital twinning capabilities at level-1, allowing for real-time monitoring and analysis of its behavior in space. The integration of digital twin technology enables proactive sensor data generation, motion detection which lead to enhanced mission planning. The design process encompasses various aspects, including the selection of components, system architecture, and integration of sensors for data capture. The development phase involves rigorous testing and validation to ensure the reliability and performance of the digitally twinned CubeSat.

In this paper, spectroscopy payload of JNANAM satellite being developed by JSS Science and Technology University, JSS Academy of Higher Education and Research in Mysuru to monitor the stability of drug samples will be explained. This is followed by description of challenges faced in interfacing triad spectroscopy sensors to On Board Computer (OBC) and result analysis of terrestrial level experiments and determination of appropriate focal distance from the drug sample required to place sensors.

The current paper proposes the design and development of a novel CubeSAT system equipped with a high-resolution multispectral camera and an onboard computer (OBC) employing deep learning algorithms for real-time anomaly detection that effectively track enemy movements. The CubeSAT is intended for defense and space applications, and has shown 87% accuracy and 0.89 ROC value training on YOLOv5 for object detection. Utilizing PEEK (poly-ether-ether-ketone) material, the CubeSAT achieves significant cost and weight reductions while maintaining high strength and temperature resistance. The proposed solution leverages a constellation of polar orbiting satellites to provide comprehensive, real-time monitoring and enhanced defense capabilities.

This paper will show 1u Cubesat designed to explore atmospheric conditions such as pressure, humidity, temperature, methane concentration, and ozone concentration at an altitude of 28km from the sea level. This 1u cube sat consists of three stacks avionics, telemetry and tracking control, and battery management system. It travelled around 80 km from the launch station. To track the cube satellite different antennas are developed in the range of VHF Frequency. The antenna received the data successfully for the entire flight time of the Cube satellite. The entire path of the cube sat is tracked by telemetry tracking and control

This paper presents a circular leaky-wave antenna (CLWA) designed on a corrugated half-mode substrate integrated waveguide. The proposed CLWA is shown to generate an orbital angular momentum (OAM) beam of Mode 2 with frequency-controlled beam-scanning capability. The conventional straight LWA is converted into a compact CLWA with a continuous long slot to create a uniform leaky-wave architecture at 17.5 to 21 GHz. This architecture is used to generate continuous phase shift within a conical beam to generate Mode 2 OAM beam of high purity and efficiency with a frequency-controlled beam-scanning of ±35° in one plane.

The paper presents a novel approach to designing holographic metasurfaces tailored for flexible beamforming antennas. Leveraging the unique properties of a flexible Rogers substrate with a thickness of 0.5 mm, the proposed metasurface enables versatile beamforming capabilities while maintaining mechanical flexibility. Specifically, the design focuses on achieving a focused beam at an angle of 12⁰ at 14.5 GHz. Through rigorous electromagnetic simulations and optimization, the metasurface is engineered to exhibit precise phase modulation and impedance matching, ensuring efficient beam steering and radiation control. The designed antenna system demonstrates impressive performance, achieving a substantial gain of approximately 13 dBi.

In this manuscript, the effect of fabrication process induced stress on pull-in behaviour of Radio Frequency Micro-Electro-Mechanical-System (RF-MEMS) switch has been analytically and experimentally studied. The effect and compensation of process residual stress on pull-in behaviour of RF-MEMS switch is discussed. Inevitable process induced residual stress is compensated up to 200Mpa in novel design. Due to such high tensile stress, in conventional fixed-fixed beam switch, measured pull-in was found 70% higher than the design value. An improved flexure based stress compensated design with low actuation voltage was designed, fabricated and characterized, wherein; pull-in voltage was measured as per design value.

This paper discusses the development of a Linear Quadratic Regulator (LQR) control for switching converters with non-minimum phase characteristics. It introduces a feedback loop with a Kalman filter to address observability issues in high-gain converters and simplify control processes. The paper examines design challenges and demonstrates the improved system performance through MATLAB/Simulink simulations.

In today's linked world, aircraft vehicles need advanced communication technologies to operate. However, this dependency makes them susceptible to cyber dangers such intrusions into communication networks. In this research, we develop a hybrid deep learning model that enhances aerospace vehicle Intrusion Detection Systems (IDS). Our cascading LSTM and GRU network model handles time-series data well, solving MIL-STD-1553 communication traffic issues. Quantitative analyses surpass machine learning in detection metrics. The model can correctly detect complex infiltration attempts with few false negatives, with accuracy and recall of 99.33% and 99.17%, respectively.

A resonant helical enclosure-backed spiral antenna, functioning on a frequency of 433 MHz, is presented in the steady state superconducting tokamak (SST-1) framework. The Proposed antenna provides notable improvements in impedance matching. Also, it exhibits in uni-direction across the spectrum, exhibiting broadside gain between 2 and 7.7 dBi, and achieving a minimum reflection coefficient of -41.16 at 433 MHz. The findings contribute to an enhanced comprehension of the interaction between the antenna and plasma. This study sets the stage for upcoming experimental inquiries, validating the efficacy of the spiral antenna configuration and promoting progress in fusion research.

Post-fabrication rectangular waveguides are required to be tested for their satisfactory electrical performance. Possible causes and mitigation is discussed in detail in this paper. Simulation and measured results for the WR-28 reference waveguides are presented. For the correction in electrical response deviation in fabricated waveguide Dent tuning of the waveguide has been explored. WR-28 waveguide performance is measured and dent tuning is attempted for the waveguide pieces. Time domain reflectometry is used for the determination of the discontinuities causing significant reflections.