| || High-angular Resolution Laser Threat Warner
Author : Kumar, Sushil;Gomekar, S. P. ;Maini, A. K.
Source : Defence Science Journal ; Vol:57(4) ; 2007 ; pp 361-365
Subject : 629.7 Aeronautics
Keywords : High-angular resolution laser threat warner;Angle-of-arrival accuracy;Field of view;Operational range;Single-pulse detection capability;False alarm rate;Weapon platform;Laserguided munitions;Visible and near-IR-pulsed solid-state laser;Azimuth and elevation direction;Defensive and offensive electrooptic counter measure;EOCM
Abstract : In this paper, the design and development aspects of a high-angular resolution laser-threat Warner developed at the Laser Science & Technology Centre (LASTEC), Delhi are presented. It describes a high-angular resolution laser-threat warner capable of giving warning with a resolution of i 3" when it is exposed to laser radiation from visible and near-IR pulsed solid-state laser source. It has a field of view of 90' in the azimuth direction, whereas the elevation coverage is between -5" and + 25". It is capable of handling multiple types of laser threats covering wavelength from 400 nm to 1100 nm and has an operational range of 4 km for a Q-switched laser source energy (10 ns) of 10 mJ/pulse and output beam divergence of 1 mrad. The paper also describes its simulated evaluation process and field-testing which it has undergone. The result of field-testing confirms that it meets all its performance specifications mentioned above.
| || Airborne Infrared Search and Track Systems
Author : Srivastava, Hari Babu;Limbu, Y. B.;Ram Saran;Kumar, Ashok
Source : Defence Science Journal ; Vol:57(5) ; 2007 ; pp 739-753
Subject : 621.38 Electronics
Keywords : Target tracking;Forward-looking infrared;Field of view;Airborne IRST systems;Infrared search and track systems;FOV;Wavelet transform;False alarm rate;Thermal imaging;FLIR;IRST
Abstract : Infrared search and track (IRST) systems are required for fighter aircraft to enable them to passively search, detect, track, classify, and prioritise multiple airborne targets under all aspects, look-up, look-down, and co-altitude conditions and engage them at as long ranges as possible. While the IRST systems have been proven in performance for ground-based and naval-based platforms, it is still facing some technical problems for airborne applications. These problems arise from uncertainty in target signature, atmospheric effects, background clutter (especially dense and varying clouds), signal and data processing algorithms to detect potential targets at long ranges and some hardware limitations such as large memory requirement to store and process wide field of view data. In this paper, an overview of airborne IRST as a system has been presented with detailed comparative simulation results of different detectionitracking algorithms and the present status of airborne IRSTs.