NASA-ISRO SAR (NISAR) is a Low Earth Orbit (LEO) observatory being jointly developed by NASA and ISRO. NISAR will map the entire globe in 12 days and provide spatially and temporally consistent data for understanding changes in Earth’s ecosystems, ice mass, vegetation biomass, sea level rise, ground water and natural hazards including earthquakes, tsunamis, volcanoes and landslides. NISAR. It carries L and S dual band Synthetic Aperture Radar (SAR), which operates with Sweep SAR technique to achieve large swath with high resolution data. The SAR payloads mounted on Integrated Radar Instrument Structure (IRIS) and the spacecraft bus are together called an observatory. Jet Propulsion Laboratories and ISRO are realizing the observatory which shall not only meet the respective national needs but also will feed the science community with data encouraging studies related to surface deformation measurements through repeat-pass InSAR technique.

NASA is responsible for providing the L-Band SAR payload system in which the ISRO supplied S-Band SAR payload and both these SAR systems will make use of a large size (about 12m diameter) common unfurl able reflector antenna . In addition, NASA would provide engineering payloads for the mission, including a Payload Data Subsystem, High-rate Science Downlink System, GPS receivers and a Solid State Recorder.

Source: ISRO