Radar (Radio Detection and Ranging) systems involve devices or instruments that use radio waves to detect the position, speed, range, altitude, movement and direction of objects outside the visible range. In Defence systems, radars are mainly employed to detect aircraft, spacecraft, ships and missiles. Aircraft altimeters use the radar principle to determine the height of the craft from the ground. A weather forecasting radar detects the position of the clouds. A traffic control radar detects the speed of fast vehicles on the roads.
Radar transmits electromagnetic signals in air at different wavelengths. The signals strike against any object in the path and get reflected. The receiver part of the radar listens to the reflected signals from which the distance, speed and other parameters pertaining to the object are estimated. The signals travel at the velocity of light (3,00,000 km per second). The distance of the object is calculated from the time taken by the transmitted signal to return. Well, this is just the basic principle. There are different types using different norms for accuracy and models for specific applications. Continuing research is being conducted for evolving new types and styles with improved efficiency.
It is sometimes claimed that radar tipped the scales in Britain’s favour in World War II, through timely warning of the invading German bombers.
LRDE
Under the control of the Defence Research and Development Organisation, an institution strives to be a centre of excellence in design and development of radars and related technologies, primarily to meet the needs of our Defence requirements: Electronics and Radar Development Establishment (LRDE), C.V. Raman Nagar, Bangalore - 560 093; Website: http://drdo.gov.in/drdo/labs/ LRDE/English/index.jsp? pg=homebody.jsp+
The LRDE was born as the Inspectorate of Scientific Stores at Rawalpindi, now in Pakistan, in 1939. It was moved to Dehradun in 1946, and renamed Technical Development Establishment (Instruments and Electronics). In 1958, the electronics activity was bifurcated into inspection and R&D. The Electronics Research and Development Establishment was formed in Bangalore. It moved to the present location in 1986.
With self-reliance as the keyword, the LRDE undertakes the development of most sophisticated radar technology with maximum indigenous content. Different innovative models of radar were developed. They include FAX Mk I radar for locating mortars and guns for artillery, the Battlefield Surveillance Radar to detect moving men and vehicles, the Local Warning Radar (LOWARD – Indra I) for the Army, the Low Flying Target Detection Radar (LFDR – Indra II) for the Air Force, Rajendra Phased Array Radar, WLR, BFSR-SR, 3D CAR, ROHINI, REVATHI, 3D-TCR, BHARANI, ASLESHA and XV-2004. Digital electronics and embedded software were used in almost all the systems.
Consequent on the policies of liberalisation and globalisation, the LRDE had to face intense competition from global radar houses, which it took up with grace and success. The LRDE marches forward in the design and development of complex, state-of-the-art ground-based and airborne radars, with the key mantras of quality and indigenous growth.
Core competencies
Radar system engineering for ground-based, ship-borne and air-borne systems.
Design and development of major sub-systems — mechanical and electronic scanning antennas, high-performance transmitters, exciters, receivers, T/R modules, digital signal and data processors and mechanical engineering.
Areas of work
Some of the specific applications developed for the three services are indicated below.
Army:
Multifunction phased array radar and 3D surveillance radar for the Akash missile weapon system.
Low-level light-weight 2D radar for mountainous terrain air defence.
3D tactical control radar for air defence.
Short-range battlefield surveillance radar.
Weapon locating radar.
Ground penetration radar.
Air Force
Active phased array radar for airborne early warning and control.
Low-level 2D air defence radar.
3D low-level lightweight radar.
3D medium range surveillance radar for air defence.
4D active array medium power radar
Airborne electronically scanned array radar for Tejas Mark II.
Ground-controlled interception
Navy
Maritime patrol radar for fixed and rotary wing aircraft.
Inverse synthetic aperture radar for maritime patrol.
3D medium range surveillance radar.
Multifunction phased array radar for air-defence ship.
Maritime patrol airborne radar for unmanned aerial vehicle.
Coastal surveillance radar.
Technologies for the civil sector.
The LRDE has made contributions to the civilian applications as well. A few of these are mentioned below.
3D medium surveillance radar for efficient handling of large air traffic.
Industrial Perimeter Surveillance Radar: lightweight battery-powered radar for surveillance of large industrial, Defence and other installations to detect intruders up to a distance of 2 km. It can detect even a crawling man.
Antennas: solutions are available in X and Ku band for air-borne and land-based radars.
Avalanche Victim Detector: can be used by high-altitude trekkers and mountaineers as life-saving device in case of burial under avalanche or any other debris. Useful in the mining sector as well
The LRDE offers challenging opportunities for researchers with keen observation and an innovative mind.
