An update on the NASA-ISRO dual-frequency DBF SAR (NISAR) mission

The National Aeronautics and Space Administration (NASA) in the United States and the Indian Space Research Organisation (ISRO) are developing a synthetic aperture radar (SAR) mission to map Earth's surface every 12 days, known as the NASA-ISRO SAR (NISAR) Mission. NISAR has two radars sharing a mechanical structure and reflector, one operating at L-band (24 cm wavelength) and the other at S-band (10 cm wavelength). To achieve wide-swath observations at both wavelengths, NISAR is designed as a reflector-feed system where the feed aperture elements are individually sampled to allow a scan-on-receive capability. In the partnership, NASA provides the instrument structure for both L- and S-band electronics, the L-band electronics, the reflector and associated boom, and an avionics payload to interface with the radar including a solid-state data recorder, high-rate Ka-band telecommunication link, and a GPS receiver. ISRO provides the spacecraft and launch vehicle, and the S-band radar electronics, and an additional high-rate Ka-band telecom package. Hardware prototyping has matured designs for engineering models, which are currently under development.