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3rd International Conference on Range Technology, ICORT 2023

作者： Kumar, Nikhil Gopinathan, Unnikrishnan Kandpal, Neeta Kumar, Ajay Defence Research and Development Organization Instruments Research and Development Establishment Dehradun India

ISBN: (纸本)9781665493314

Distant aerial threats observed from Missile Approach Warning System (MAWS) appear as point targets therefore point target detection is a significant field of research for the defence sector. In the current work, the authors have carried out an analysis of three distinct combinations of algorithms for point target detection: Top Hat Morphology(THM) with a fixed global threshold, THM with adaptive threshold and THM with corner detection. A number of IR video sequences of sky background are recorded with an ultra wide FOV IR sensor and Gaussian blurred point targets with predefined trajectory have been overlaid on this. In this way a synthetic video data-set has been generated. Authors have used three variants of dataset: 14-bit uncompressed, 8-bit linearly compressed and 8-bit non linearly compressed for performance analysis. Probability of detection and false alarms per frame have been considered as performance measure. Analysis for execution time has also been carried out. © 2023 IEEE.

关键词： Morphology

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Signal Noise Reduction Algorithm for Object Localization and Tracking Using a 2-Dimensional Ultrasonic Sensor Array 8

Signal Noise Reduction Algorithm for Object Localization and...

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8th IEEE International Conference on Computational System and Information Technology for Sustainable Solutions, CSITSS 2024

作者： Jain, Sambhav Singh, Kuldeep Delhi Technological University Dept. of Mechanical Engineering Delhi 110042 India Defence Research and Development Organization Combat Vehicles Research and Development Establishment Chennai60054 India

ISBN: (纸本)9798331505462

Ultrasonic sensors return time of flight (TOF) readings;by producing inaudible sound waves and calculating the time they take to return to the sensors. When arranged in an array (containing multiple sensors) they can have various applications, both independently and in conjunction with other transducers and cameras. One of the most common applications that has been developed in the last couple of decades has been object detection, localization and tracking. This research paper presents a novel algorithm that addresses one of the biggest challenges with using ultrasonic sensor arrays for object localization - signal noise. The proposed system also includes a laser module mounted on a pan-tilt motor mechanism to track objects, utilizing the signal noise reduction and angles calculation algorithm. The improvement in signal quality has been quantified with signal-to-noise ratio (SNR) and mean squared error (MSE). The presented algorithm will significantly improve the application of ultrasonic sensors, in autonomous vehicles, robotics and industrial automation. © 2024 IEEE.

关键词： Signal to noise ratio

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Studies on Metasurface Geometries for Scan Enhancement in Phased Array Antennas

Studies on Metasurface Geometries for Scan Enhancement in Ph...

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2024 IEEE Microwaves, Antennas, and Propagation Conference, MAPCON 2024

作者： Kedar, Ashutosh Amogh, G. Mahesh, A. Shushrutha, K.S. Kumar, Pramod Electronics & Radar Development Establishment Defence Research & Development Organization Bengaluru560 093 India Centre of Excellence Smart Antenna Systems and Measurements R V College of Engineering Bengaluru560 059 India

ISBN: (纸本)9798350379693

This paper investigates the application of Phase Gradient Metasurfaces (PGMS) in Phased Array Antennas (PAA) to enhance beam steering capabilities, which is crucial for achieving rapid and precise control over radiation patterns. A comprehensive analysis of various geometrical topologies of PGMS unit cells is carried out focusing on optimizing both transmittance and phase distribution to maximize the performance. By identifying the optimal unit cell design, PGMS supercells and arrays tuned to operate at frequencies of 5.65GHz and 8GHz are designed. The integration of these PGMS structures atop the PAA is validated via full-wave simulations in Ansys HFSS, demonstrating significant improvements in beam scanning range. © 2024 IEEE.

关键词： Antenna phased arrays

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Flood modeling using GIS-based analytical hierarchy process in Gandak river basin of Indian territory

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Natural Hazards 2025年 1-43页

作者： Patel, Sunil Kumar Ghosh, Parthapratim Sen Gupta, Dev Kumar, Anjanay Department of Geology Institute of Science Banaras Hindu University Varanasi India Defence Geoinformatics Research Establishment Defence Research and Development Organization Chandigarh India

Flood events in recent years have increased as a major catastrophic event and India is listed among top nations in the globe. The Gandak river basin in Indian Territory puts heavy flood situations every year and the present study was done to classify it into flood susceptible zones using analytical hierarchical process (AHP). The AHP was implemented through a series of steps, including the multicollinearity test, creation of a pairwise comparison matrix, the assignment of weights, consistency check, sensitivity analysis and weighted overlay analysis using ArcGIS V.10.5 platform. The Consistency Ratio (CR) values showed perfect consistency when calculated for each thematic parameter as the values were below 0.1 or 10% showing high acceptance for AHP model to run. To attain dependable precision, the study incorporated a substantial number of thematic layers (N = 12 for FSZ) and conducted multicollinearity analysis of these variables to address issues related to high correlation among them using SPSS. For the multicollinearity check, the tolerance value should be greater than 0.1, and the percentage of variance inflation factor (VIF) should be less than 10 for the accuracy evaluation of this test. The AHP was successfully employed in the present area and flood susceptibility zone (FSZ) map generated revealed elevation and slope were dominant factors affecting FSZ map. The map removal sensitivity analysis and single parameter sensitivity analysis described the importance of elevation and slope in the final FSZ map. The high flood susceptibility region mostly lies in the southern part of the study area and percent cover under high and very high is around 44.19% reflecting regions suffering extreme conditions of flood during monsoon season. Very low and low flood zones are situated in northern part of the basin which clearly indicates that slope and elevation are the predominant factors controlling the flood zones. The AUC/ ROC curve value was 83.60%. The current stu

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Laser powder bed fusion technique of hydrogen–fueled gas turbine: Role of advanced materials and its challenges

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Materials Today: Proceedings 2023年 90卷 11-14页

作者： Harithsa S.N. Anand Kumar S. Velu R. Nagesha B.K. Additive Manufacturing Research Laboratory Department of Mechanical Engineering Indian Institute of Technology Jammu Jammu 181221 India Gas Turbine Research Establishment Defence Research and Development Organization Bangalore 560093 India

Aviation accounts for 1.9% of greenhouse gas emissions, decarbonization is not straightforward as electrification is not feasible, and biofuels only partially address the issue. Therefore, aero-engine manufacturers are looking towards hydrogen as a clean fuel source as the emissions would majorly be water with no lasting greenhouse gasses. The major challenge with hydrogen-firing engines would be high firing temperatures, corrosive exhaust gasses and adverse reactions with structural components. The design flexibility of additive manufacturing (AM) and advanced materials development, such as high entropy alloys (HEAs) can be combined to produce gas turbines with higher turbine inlet temperatures and power output. This paper discusses the advantages and issues with hydrogen as fuel, the role of AM and advanced materials suitable for hydrogen-firing engines. © 2023

关键词： Additive manufacturing Aeroengine High entropy alloys Hydrogen fuel Laser powder bed fusion technique

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Anisotropic yielding performance of additively manufactured Inconel 718: Effect of thermal treatment

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Materials Today: Proceedings 2022年 70卷 339-344页

作者： Shrivastava, Abhishek Anand Kumar, S. Rao, Samrat Nagesha, B.K. Additive Manufacturing Research Laboratory Department of Mechanical Engineering IIT Jammu J&K 181221 Jammu India Gas Turbine Research Establishment Defence Research and Development Organization Bangalore 560093 India

Texture develops in metallic materials as a result of manufacturing operations. The laser powder bed fusion (LPBF) technique involves complex thermal behaviour causing directional solidification thus leading to a high degree of texture. Additively manufactured Inconel 718 alloy finds various applications in aerospace components subjected to extreme operating conditions. Thus it becomes necessary to identify the comprehensive anisotropic behaviour to understand the component's performance in the end application. In this paper, the anisotropy of Inconel 718 alloy has been evaluated qualitatively using the Knoop hardness test. The anisotropy of yield loci is reduced after heat treatment. The reduction in the area of the yield locus after thermal treatment symbolizes texture softening of the component. © 2022

关键词： Heat treatment

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Point Target Detection for MAWS Application

Point Target Detection for MAWS Application

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Range Technology (ICORT), International Conference on

作者： Nikhil Kumar Unnikrishnan Gopinathan Neeta Kandpal Ajay Kumar Instruments Research and Development Establishment Defence Research and Development Organization Dehradun India

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Laser powder bed fusion technique of hydrogen-fueled gas turbine: Role of advanced materials and its challenges

Laser powder bed fusion technique of hydrogen-fueled gas tur...

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2nd International Conference on Future Technologies in Manufacturing, Automation, Design and Energy

作者： Harithsa, Shreyas Nandakumar Anand Kumar, S. Velu, Rajkumar Nagesha, B.K. Additive Manufacturing Research Laboratory Department of Mechanical Engineering Indian Institute of Technology Jammu Jammu181221 India Gas Turbine Research Establishment Defence Research and Development Organization Bangalore560093 India

ISBN: (纸本)9789819912902

关键词： 3D printing

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Luneberg lens as passive radar augmenter for aerial target 2

Luneberg lens as passive radar augmenter for aerial target

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2nd International Conference on Range Technology, ICORT 2021

作者： Biswas, Diptiman Rizwan, Asif Kumar, Narendar Nithin Raj, V.N. Aeronautical Development Establishment Defence Research Development Organization Bangalore India

ISBN: (纸本)9781665449564

Aerial targets with required level of signature augmentation are used for artillery exercises. The Luneberg lens is a class of optical devices that finds potential applicability as passive radar augmenters for aerial target systems such as drones, tow-bodies etc. They effectively simulate dynamic target by providing mono-static radio frequency echo in the direction of radar required for the drills. The lens is a spherically symmetric structure and made of nonhomogenous dielectric material where refractive index (n) decreases radially from the center to the outer surface. It can produce radar cross-section that measures several hundred times that of a metallic sphere of same size. In practice, it is developed by layered assembly of discrete concentric shells, each of a different refractive index. A chosen portion of its outer surface is masked with a thin conductive layer for reflection. A comprehensive study has been carried out to configure, simulate and evaluate the performance of a compact Luneberg lens and have been discussed. Further, to achieve required detectability of an indigenous aerial tow-target system with specific RCS coverage, multiple lenses placed in different orientations have been configured and reported. © 2021 IEEE.

关键词： Refractive index

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Kalman Filter Based Point Target Tracking

Kalman Filter Based Point Target Tracking

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International Conference on Optics and Electro-optics, ICOL 2019

作者： Kumar, Nikhil Massey, Meenakshi Kandpal, Neeta Instruments Research and Development Establishment Defence Research and Development Organization Dehradun248008 India

ISBN: (纸本)9789811592584

The detection and tracking of point targets in cluttered environment has always played a significant role in surveillance and navigation applications especially for aerial targets. Most of the contemporary MWS (Missile Warning Systems) and IRST (Infra Red Search and Track) systems use captured IR radiations from the scene for detection and tracking of such point targets. The unintended IR (Infra Red) radiations emitted from targets make the signatures more prominent than background and clutter, this contrast is commonly used as a clue for detection of targets. The present approach also relies on this contrast based clue. On the basis of statistical analysis of image content of row and column vectors and Kalman filtering, the location of the point target is explored in the considered frame of the video sequence. A dataset of synthetic video sequences having point target with variable SNR is generated to validate the proposed method. The results obtained demonstrate effectiveness and robustness of the approach. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Kalman filters

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