The RISAT series of satellites developed by ISRO use _______ radar for earth observation.
- Optical
- Synthetic Aperture Radar (SAR)
- Infrared
- Ultraviolet
Answer: Synthetic Aperture Radar (SAR)
RISAT (Radar Imaging Satellite) series uses Synthetic Aperture Radar (SAR) technology, which allows imaging day and night, and through cloud cover, unlike optical satellites.