- Why in News- A forthcoming satellite, NISAR will map the most earthquake prone regions in the Himalayas with unprecedented regularity.
- NISAR is being jointly developed by the Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA) of the U.S.
- NISAR mapping data this can potentially give advance warning of land subsidence, as recently observed in Joshimath, Uttarakhand, as well point to places that are at greatest risk from earthquakes.
- The NISAR satellite, expected to cost approximately $900 million (with ISRO contributing about onet-enth) will use two frequency bands:
- the L band and S band to image the seismically active Himalayan region that will, every 12 days, create a “deformation map”.
- These two frequency bands will together provide high-resolution, all-weather data from the satellite that is expected to follow a sun synchronous orbit and will be launched in January 2024.
- Scientists from the Geological Survey of India in 2021 published a “strain map” of the Himalayas based on data from 1,252 GPS stations along the Himalayas.
- It identified regions that had the greatest odds of generating earthquakes of magnitude above 8 and their extent.
- These many stations are still too few and there’s only one satellite (Sentinel) that we rely on right now.
- With NISAR, the costliest space mission ever, we can have a game-changer in earth science observation.
- With a frequency of 12 days and the ability to be able to provide images even under cloudy conditions, NISAR would be a valuable tool to study deformation patterns, such as in Joshimath.
- Key facts about NISAR:
- NISAR is a Low Earth Orbit (LEO) observatory jointly developed by NASA and ISRO.
- It is an SUV-size satellite weighing 2,800 kilograms.
- It consists of both L-band and S-band synthetic aperture radar (SAR) instruments, which makes it a dual-frequency imaging radar satellite.
- 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.
- SAR is capable of penetrating clouds and can collect data day and night regardless of the weather conditions.
- NASA has provided the L-band radar, GPS, a high-capacity solid-state recorder to store data, and a payload data subsystem. ISRO has provided the S-band radar, the GSLV launch system, and spacecraft
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- It also consists of a large 39-foot stationary antenna reflector made of a gold-plated wire mesh which will be used to focus “the radar signals emitted and received by the upward-facing feed on the instrument structure.
- Mission Objectives:
- It will measure Earth’s changing ecosystems, dynamic surfaces, and ice masses, providing information about biomass, natural hazards, sea level rise, and groundwater.
NISAR will observe Earth’s land and ice-covered surfaces globally with 12-day regularity on ascending and descending passes.
