Vol 13 Issue 4 October 2025-December 2025

Abstract: PolSAR has become a significant focus of research due to its wide-ranging applications in structural monitoring, foliage penetration, and target detection. Despite its potential, work on FOPEN remains limited and often inconsistent, largely because forest environments differ considerably in structure and density. Integrating PolSAR with FOPEN techniques enhances the ability to detect obscured targets by exploiting polarization dependent scattering information that conventional radars cannot provide. This review outlines the limitations of traditional radar architectures, particularly their reduced capability for accurate image formation in complex environments, and highlights how SAR and PolSAR systems address these challenges through improved resolution, diverse polarization modes, and enhanced interpretability. A comprehensive examination and comparison of existing literature is presented, synthesizing current methods and insights relevant to PolSAR based FOPEN studies.

Keywords: Radar, SAR, PolSAR, Imaging, FOPEN.

Title: A Review on PolSAR for FOPEN Applications

Author: Afaan Shaikh, Kalyani Rajput, Nidhi Korat, A Arockia Bazil Raj, N D Kuchekar, P S Deshpande

International Journal of Engineering Research and Reviews

ISSN 2348-697X (Online)

Vol. 13, Issue 4, October 2025 - December 2025

Page No: 55-71

Research Publish Journals

Website: www.researchpublish.com

Published Date: 24-December-2025

Amendment Date: 09-April-2026

Abstract: The use of Small Unmanned Aerial Vehicle (SUAV’s) is rapidly increasing in civilian and military applications, but their cost, accessibility and easy usage make them potential tools for malicious activities. This review presents a comprehensive analysis of current SUAV detection and classification techniques. The SUAV detection methods include Radar Based Sensing, RF signal analysis, Acoustic signatures and Vision based systems. Findings show that single-sensor methods are insufficient, while hybrid approaches combining micro-Doppler, RF, and acoustic signatures offer higher detection accuracy. For precise SUAV navigation, this review discusses RTK GPS technology which uses carrier phase measurements and Integer ambiguity resolution by LAMBDA method for sub-centimetre accuracy. This paper also discusses IMU sensor integration with GPS sensor to provide high accuracy and real time positioning and navigation. The study also analyses Line of Sight (LOS) alignment strategies for air-to-ground and air-to-air communication, comparing gimbal-based alignment with monopulse tracking and FSOC based approaches. While gimbal mechanisms are reliable but slow, monopulse and EKF-based methods provide faster and more precise alignment. Overall, effective SUAV surveillance requires multi-sensor integration, advanced signal processing, and robust communication links. Future improvements in AI-driven fusion, swarm-based detection, GNSS alternatives, and autonomous FSO alignment can significantly enhance system reliability and performance.

Keywords: SUAV, Micro-Doppler, RTK GPS, NMEA, RTCM, LoRa, NTRIP.

Title: Review on SUAV targets positioning and tracking with RTK GPS systems for LOS maintenance

Author: Aryan Mahindre, Aditya Raut, A.A. Bazil Raj, G. N. Gaikwad

International Journal of Engineering Research and Reviews

ISSN 2348-697X (Online)

Vol. 13, Issue 4, October 2025 - December 2025

Page No: 38-54

Research Publish Journals

Website: www.researchpublish.com

Published Date: 10-December-2025

Abstract: Foliage-penetration (FOPEN) radar systems operating in VHF/UHF bands enable detection of man-made targets concealed beneath dense vegetation, yet their performance is significantly constrained by strong, non-Gaussian, and temporally varying foliage clutter. Traditional signal-domain techniques such as MTI/MTD filtering, CFAR variants, adaptive LMS/RLS cancellation, entropy-weighted coherent integration, and blind-source separation methods provide only partial suppression under wind-induced decorrelation, multipath propagation, and low signal-to-clutter ratios. In parallel, image-processing strategies including diffusion filtering, Total Variation and Forward–Backward Diffusion models, anisotropic diffusion, RPCA/TV-RPCA decomposition, and background-subtraction families enhance clutter rejection in Range-Time-Intensity (RTI), Range–Doppler (RD), and spectrogram formats by exploiting spatial–temporal structure. Recent advances in machine learning and deep networks such as CNNs, autoencoders, hybrid feature-fusion architectures, and learned Doppler-feature representations further improve target localization and classification by modeling nonlinear clutter characteristics directly from radar imagery. Also, Synthetic Aperture Radar (SAR)-based FOPEN imaging provides a complementary pathway for clutter suppression. Techniques including coherent and incoherent change detection, spectral intersection filtering, circular-aperture angular correlation (ACF/FCF), physical-optics modeling, deterministic-aided STAP, and multi-channel interferometric imaging significantly improve background suppression and moving-target detection in dense forests. This paper presents a comprehensive review of signal-domain, image-domain, machine-learning, and SAR-based clutter-cancellation techniques for FOPEN radar. The review focuses on a number of key aspects, including theoretical principles, algorithmic implementation, strengths, limitations, and realistic performance in a wide range of forest environments. Such unification of classical radar processing with modern SAR imaging and deep learning presents a comprehensive reference to guide future research toward high-accuracy detection, classification, and tracking of hidden targets beneath dense vegetation.

Keywords: FOPEN, STAP, ACF/FCF, SAR, FBD, Image Processing, Clutter cancellation.

Title: A Review on Image Processing Techniques on FOPEN Radar Clutter Cancellation

Author: Gouresh Desai, Prasad Saratkar, Sohan Salunkhe, Sakshi Fulsundar, A. A. Bazil Raj

International Journal of Engineering Research and Reviews

ISSN 2348-697X (Online)

Vol. 13, Issue 4, October 2025 - December 2025

Page No: 11-37

Research Publish Journals

Website: www.researchpublish.com

Published Date: 10-December-2025

Abstract: Previous studies identified key barriers to implementing decarbonisation strategies in change resistant organizational structures. Consequently this paper proposes a strategic research agenda focused on the decision-making behaviours of CEOs. Central to which being their risk perceptions and leadership models adopted. The analysis highlights five priority research areas: (1) how CEOs integrate regulatory pressures, financial constraints, and stakeholder expectation in decision-making; (2) evaluating leadership training programmes aimed at executives driving decarbonization initiatives; (3)Eeinvestigating board-level sustainability mandates on corporate environmental strategies; (4) assessing CEO-driven innovation accelerating adoption of low-carbon practices; and (5) exploring how corporate leadership actively facilitates or impedes sustainable transformation. By synthesizing economic, organizational, and policy considerations, this research agenda provides a framework for understanding CEO influence on corporate commitments to successful sustainability transitions.

Keywords: Decarbonization, Built Environment, Green Hydrogen, CEO decision-making, Sustainable Transformation.

Title: Decarbonisation of the Built Environment: the CEO Factor

Author: Dr Olga Lozova

International Journal of Engineering Research and Reviews

ISSN 2348-697X (Online)

Vol. 13, Issue 4, October 2025 - December 2025

Page No: 1-10

Research Publish Journals

Website: www.researchpublish.com

Published Date: 08-October-2025