Rajendra Radar - Description

Description

Rajendra is a slewable passive phased array radar used for 3-D target detection, multi target tracking and multiple missile guidance under extreme hostile EW environment. It makes use of a passive phased array to search a volume of space, distinguish between hostile and friendly targets, automatically track up to 64 targets and command one of several launchers to engage up to 4 targets simultaneously. Initially designed as a standalone system, Rajendra is now equipped with the ability to integrate with a network of sensors, including long and medium-range surveillance radars of foreign and indigenous origin.

Rajendra's multi-element antenna arrangement folds flat when the vehicle is in motion. The Radar consists of a surveillance antenna array with 4000 phase control modules (PCM's) operating in the G/H-Band (4-8 GHz), engagement antenna array with 1000 PCM's operating in the I/J-Band (8-20 GHz), a 16-element IFF array and steering units. A powerful high-end computer computes phases for all the elements of the array. Rajendra controls the beam positioning sequence through beam requests for each track at adaptive data rates and performs multifunctional roles like search –confirm –track -interrogate targets, assign and lock on launchers, and launch/acquire/ track/guide missiles. The RDP supplies track data to remote group control centre. Rajendra features a Dual channel radar receiver and a C band transmitter, although the complete transmitting and receiving features and bands are unknown.

Rajendra radar uses phase shifters integrated in large numbers for electronic beam steering. This allows Rajendra radar to simultaneously track multiple aircraft and also guide multiple missiles towards these targets. The phase shifter was designed and developed by Prof Bharati Bhat, a scientist from Centre for Applied Research in Electronics (CARE) of IIT, Delhi, and her team.

The phased array radar rotates 360 degrees on a rotating turnstile at a moderate speed. This allows it to perform 360 degree surveillance. The phased array itself has 45 degree scan limits to either side, giving a total scan coverage of 90 degrees, if the radar array is static.

During Multisensor Tracking a 2-D battery surveillance radar (BSR) with 360 degree coverage and a larger detection range provides track data to the multifunction, slewable, 3-D phased array radar. This is useful when a single battery of the Rajendra is detached from the group to fight alone, and early warning from the 3-D CAR is not available. The 2-D BSR data is then integrated by the Rajendra's radar vehicle. The multisensor direction finder in Rajendra processes the track data from the phased array radar and the BSR to identify the targets reported by both the sensors and maintains a common track database. For those BSR tracks, which are not being reported by Rajendra though under its coverage, target acquisition is initiated with elevation search in the designated direction. The antenna is skewed in the direction of threat to acquire the targets, which are outside the covered air space. The Rajendra's tracking range is 60 km against fighter aircraft flying at medium altitude.

The major functions of the Rajendra are:

• Surveillance of the assigned volume of space
• Acquisition of aircraft targets either independently or handed over from group control centre via the 3-D CAR or from the battery surveillance radar
• Tracking of targets (64)
• Tracking of assigned targets (up to 4) and missiles (up to 8) during engagement
• Command guidance of missiles (up to 8)
• Integrated IFF (Identification Friend or Foe) functions