The NASA-ISRO Synthetic Aperture Radar (NISAR) is a joint Earth observation satellite mission, representing a collaboration between the Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA). The partnership agreement for this mission was signed in September 2014. The satellite was successfully launched aboard an ISRO Geosynchronous Satellite Launch Vehicle (GSLV-F16) rocket on July 30, 2025, from the Satish Dhawan Space Center in Sriharikota.
The mission was created to make global measurements of the causes and consequences of land surface changes, addressing priorities in Earth science like ecosystems, crustal deformation, and cryospheric sciences. NISAR is the world's first Earth observation satellite to carry dual-frequency Synthetic Aperture Radars (SAR) on a single platform. It uses an L-band radar provided by NASA and an S-band radar provided by ISRO. This dual-band SAR technology allows it to penetrate clouds and darkness, providing high-resolution, all-weather, day-and-night imagery.
The satellite maps the Earth's land and ice masses, revisiting each location every 12 days. The L-band radar is particularly useful as it can penetrate forest canopies and soil to detect underground changes. The data collected will be used to monitor complex natural processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards like earthquakes and landslides. For Indian users, the data will be processed and distributed by the National Remote Sensing Centre. The core mechanism of the dual-band SAR mission has remained consistent since the partnership was established.