Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The RADAR system generally consists of a transmitter which produces an electromagnetic signal which is radiated into space by an antenna. When this signal strikes any object, it gets reflected or reradiated in many directions. This reflected signal is received by the radar antenna which delivers it to the receiver, where it is processed to determine the geographical statistics of the object. Radar is still most familiar as a military technology. Radar antennas mounted at airports or other ground stations can be used to detect approaching enemy airplanes or missiles, for example. In India, Electronics and Radar Development Establishment (LRDE) is the laboratory that comes under Defence Research & Development Organisation ( DRDO ) which is responsible for development of radars. This organisation has met success with various radar systems developed by it being inducted in Indian Armed Forces now in large numbers.
The Indian Doppler Radar (INDRA) series of 2D radars were developed by India’s DRDO for the Army and Air Force. The INDRA-I is a is a mobile surveillance radar for low level target detection while the INDRA-II is for ground controlled interception of targets.
INDRA-I is a 2D mobile surveillance radar for low level target detection. The radar is housed in two wheeled vehicles. Some of the main features are automated Track While Scan (TWS), integrated IFF and high scan rate for high speed target detection. The radar is produced by Bharat Electronics Limited and inducted into service. The INDRA-I was a landmark project for the DRDO, as it was the first large radar system designed by the organization and produced in number for the defence forces.
It is a multifunction electronically scanned phased array Radar which is the heart of Aakash Air Defence System. It is a passive electronically scanned array (PESA) radar and is used to guide Aakash missile to its target. Mounted on a two wheeled vehicle it fulfills multiple radar functions like surveillance, tracking and guidance. It is a multifunction radar, capable of surveillance, tracking and engaging low radar cross section targets. It is the heart of the Akash surface-to-air missile system and is the primary fire control sensor for an Akash battery.
The Rohini is an operating in S-Band ground based 3D medium range air surveillance radar providing detection and tracking air targets even under hostile EW operational environment. It is capable of handling multiple targets simultaneously and also precisely calculate the height at which projectiles are flying. Mounted on Tatra mobile platform, a heavy duty modified truck built by the public sector Bharat Earth Movers Limited (BEML) and supported by an auxiliary mobile power unit, it enables the Rohini to be easily transported to the battlefront.
Operating in a range of upto 170 kilometres and an altitude of 15 kilometres, the Rohini radar can track multiple targets like fighter jets and missiles travelling at supersonic speeds of over 3,000 kms per hour. The radar employs an array of Electronic Counter Counter Measure (ECCM) features including frequency agility and jammer analysis. A Secondary Surveillance Radar, IFF, is integrated with the primary radar Rohini, which distinguishes friendly and hostile aircraft. About 100 pieces are expected to be built, with around 20 radars being manufactured every year.
Swathi Weapon Locating Radar:
Swathi Weapon Locating Radar is a mobile artillery locating phased array radar developed by India. It is a counter-battery radar designed to detect and track incoming artillery and rocket fire to determine the point of origin for Counter-battery fire. It has been developed by DRDO’s Bangalore base laboratory, LRDE and the Government owned Bharat Electronics Limited (BEL). It can track 7 targets at a single time and are helpful for Indian Army to locate Pakistani artillery positions across the LOC.
The aerostats are large fabric envelopes filled with helium, and can rise up to an altitude of 15,000 feet (4,600 m) while tethered by a single cable. The largest lifts a 1000 kg payload to an operating altitude providing low-level, downward-looking radar coverage. The first aerostats were assigned to the United States Air Force in December 1980 at Cudjoe Key, Fla. During the 1980s, the U.S. Customs Service operated a network of aerostats to help counter illegal drug trafficking.