Sisir Radar Private Ltd, a startup in the space sector, has developed a synthetic aperture radar (SAR). Traditionally used on satellites for cloud-penetrating observations, Sisir Radar has successfully adapted SAR technology for drones and cars, detecting signatures at a 1.5 km range. Tapan Misra, the Founding Director and Chief Scientist, highlighted the advantage of a mobile SAR radar, being less susceptible to attacks compared to larger conventional surveillance radars. Previously a Director at the Space Applications Centre of ISRO, Misra played a key role in developing ISRO's RISAT series of SAR satellites and the Dual Frequency SAR on the Chandrayaan 2 orbiter.

According to Misra, utilizing a radar with coarse angular resolution and a small antenna, the car moved and detected signals. Through signal processing, these signals were transformed into a high angular resolution synthetic aperture radar (SAR) image in a ground-gazing view. Misra highlighted that the SAR on the car successfully penetrated foliage, capturing signatures at a 1.5 km distance. The vehicle exhibited variable speeds, eliminating the necessity for a constant or stationary movement. The SAR effectively identified metallic objects, fences, buildings, and more. Managing motion compensation posed significant challenges compared to traditional SAR processing, considering the varying speeds of the CAR-SAR, ranging from 0 kmph to 50 kmph, including intermittent stops. The implementation of motion compensation for this innovation required substantial effort.

Synthetic Aperture Radar (SAR) is a specialized imaging radar technology capable of delivering highly accurate, high-resolution terrain imagery even in challenging conditions such as clouds, smoke, dust, and complete darkness. SAR imagery surpasses other remote sensing technologies like hyperspectral and multispectral in terms of resolution. This technology plays a crucial role in strategic reconnaissance, planning, and disaster management. Sisir Radar recently achieved success in the prestigious iDEX DefSpace Challenge with its initiatives involving the development of "L and P band Continuous Wave SAR payload for LEO Small Satellites" and "Unfurlable, Electronically Steering Antenna for L and P band SAR payload" designed for the Indian Air Force (IAF).