Indian Space Research Organisation (ISRO) has completed the development of a Synthetic Aperture Radar (SAR) capable of producing extremely high-resolution images for a joint Earth Observation (EO) satellite mission with NASA — NASA-ISRO SAR (NISAR) is a joint collaboration for a dual-frequency, L and S-band, SAR for EO.
NASA and ISRO signed a partnership on September 30, 2014, to collaborate on and launch NISAR (artistic rendition above, courtesy of NASA +JPL). The mission is targeted to launch in 2022 from ISRO’s Sriharikota spaceport. NASA is providing the mission’s L-band SAR, a high-rate communication subsystem for science data, GPS receivers, a solid-state recorder and payload data subsystem.
Photo of the ISRO’s Sriharikota spaceport with a launch underway.
ISRO is providing the spacecraft bus, the S-band radar, the launch vehicle and associated launch services for the mission. The goal of the mission is to make global measurements of the causes and consequences of land surface changes using advanced radar imaging.
The S-band SAR payload of NISAR satellite mission was flagged off by the Secretary in the Department of Space and ISRO Chairman K Sivan on March 4. The payload has been shipped from ISRO’s Ahmedabad-based Space Applications Centre (SAC) to NASA’s Jet Propulsion Laboratory (JPL) at Pasadena in the U.S. for integration with the latter’s L-band SAR payload, according to an ISRO statement said. SAR produces extremely high-resolution images and the radar penetrates clouds and darkness, thereby enabling NISAR to collect data day and night in any weather conditions.
NASA added that the mission will measure Earth’s changing ecosystems, dynamic surfaces and ice masses, providing information about biomass, natural hazards, sea level rise and groundwater, and will support a host of other applications.
“NISAR will be the first satellite mission to use two different radar frequencies (L-band and S-band) to measure changes in our planet’s surface less than a centimetre across. NISAR will observe Earth’s land and ice-covered surfaces globally with 12-day regularity on ascending and descending passes, sampling Earth on average every six days for a baseline three-year mission. This allows the mission to observe a wide range of Earth processes, from the flow rates of glaciers and ice sheets to the dynamics of earthquakes and volcanoes,” according to NASA.
“NISAR would provide a means of disentangling highly spatial and temporally complex processes ranging from ecosystem disturbances to ice sheet collapses and natural hazards including earthquakes, tsunamis, volcanoes and landslides. Over the course of multiple orbits, the radar images will allow users to track changes in croplands and hazard sites, as well as to monitor ongoing crises such as volcanic eruptions. The images will be detailed enough to show local changes and broad enough to measure regional trends. The instrument’s imaging swath the width of the strip of data collected along the length of the orbit track is greater than 150 miles (240km), which allows it to image the entire Earth in 12 days,” ISRO said.
