Indian Airforce Surveillance Radar
Radar is the key for watching the airspace and allows the Fighters to correct Direction, India operates number of Ground Based Radar's for Tracking and detecting friendly and enemy airborne targets.
Those Stationary Radars have Huge power plus long tracking ranges. those Radar can be classified as per it's power and Range.
Aerostat Radars is the one of the key Radar which can detect and track enemy airborne targets. IAF operates two or more Aerostats which was built by IAI Israel. those Radars act as a AEWCS, where the Radar is also placed in the heights of some 100meters for better detection for even low flying Targets. which is very helpful for mountain terrains.
The EL/M 2083 is an aerostat AESA radar, the tracking and surveillance data's can be sent through command or field stations in real time for quick reactions. the EL/M 2083 can track targets at the around 400km radius.
High Power Radar.
Usually Stationary, Long range Radar, Basically built in Tower, can track targets in 3 dimensional, which means it can provide exact informations about the Target range, bearings, elevation and Azimuth. High power radar can work round a clock all day include monitoring the weather.
India operates more than six High power THD 1955 Radars, they can track targets nearly 1000 Kilometers, for stable and controlled watch IAF down powered the Radar to track targets upto some 500 kilometers, Those are all developed by Indian owned BEL company with foreign Assistance. those Radar's gone massive upgrades for improved survivability in dense EMP and Electronic Jamming. the upgrades were done by French firm Thales, the THD 1955 uses the S band for communication for faster refresh and data Transfer.
DRDO also in works to design a modern more powerful Radar, which is High power Long Range with 4D view.
Medium Powered Radar
The Second layer of Air surveillance can be achieved by Medium powered AESA radar's, this can be mobile allows it can be transported quickly based on possible infiltration area's, such as Deep valley's blind zones,etc. India uses the Israeli made EL/M 2084 Multi mode radar, which is medium powered. this one not only works as a Surveillance but can Guide the Interceptor missiles to the detected Threat.
It's also a 3D AESA radar which can be used for both Air surveillance and Weapon locating, the Radar can rotate at the rate of 30 rounds per minutes allows them to view entire 360 degree of view, the reported range of the radar is 250 kilometers,
The same can be work with Modern surface to air missiles like SpyDer and Barak 8, can guide those missile if it detects and identified it's a Hostile threat. it can also be assigned to eliminate Ballistic missile too
Israel transfered the Technical data's to DRDO to build such Radars in Home, while they already built and deployed some unknown numbers of the Radar's all over India.
There is another Radar in the making known as Arudhra MPR, which is based on the Thompson Master T, a 4D MPR radar.
LLTR ( Low Level Transportable Radar )
The common battlefield Radar, mostly fitted on the wheels, Most IAF battlefield Radars uses the ural and tatra Trucks which currently being replaced with Indian made TATA vehicles. thus can be used mostly for combined with short range SAM systems, like S 125 and other old soviet Radars, currently those old systems are replaced by newer Thales GM 200 AESA radar along with Indian made Ashwini Radar which is developed with the Help of Thales.
the Thales GM 200 is an medium range multi mission radar with the Range of upto 200kilometer. with the Rotating Radar it can search targets in all sides ( 360 degree). the Radar even detects Hovering Helicopters, low level battlefield UAV's,other informations are not available for Public release.
LLLWR- Low level Light weight Radar
This is the low range for combat deployment, mostly carried by foots and deployed quickly for detecting low flying airborne threats like UAV's and Helicopters it can aslo search and track Fighter jets and Transport planes.
BEL designed a Ashlesha LLLWR for the IAF and IA to use in all terrian conditions, with the inbuilt IFF ( Identification of Friend or Foe ) the ground unit can get extra informations about Airborne Targets nearby their operational area's.