NISAR Satellite to Map Himalayas

• 17 Apr 2023

Recently, the Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA) of the U.S. have jointly developed a satellite called NISAR (NASA-ISRO Synthetic Aperture Radar) that will map the most earthquake-prone regions in the Himalayas.

• This satellite is expected to launch in January 2024.
• It will use two frequency bands, L-band and S-band, to image the seismically active Himalayan region.
• The satellite will create a "deformation map" every 12 days, allowing the geoscience community to determine how strain is building up in various parts of the Himalayas.
• The satellite will serve as a valuable tool to give warning of land subsidence, allowing scientists to study deformation patterns, such as those recently observed in Joshimath, Uttarakhand, under all-weather conditions.
• NISAR will provide high-resolution, all-weather data that can show how mountains and geological formations are changing over time.
• NISAR will follow a sun-synchronous orbit and is expected to cost approximately $900 million, with ISRO contributing about one-tenth.
• The data collected by NISAR can potentially give advance warning of land subsidence and point to places that are at greatest risk from earthquakes.
• Ground-based observatories can provide early warning by picking up underground waves that result from an earthquake, but satellites can provide valuable information to geologists and seismologists by imaging a wide swath from a distance.
• NISAR is expected to be the costliest space mission ever, but it will be a game-changer in earth-science observation and provide valuable information to prevent loss of life and property in the Himalayan region.

The L-band and S-band has a wavelength of about 24 centimeters and is able to penetrate through vegetation, providing data on the subsurface topography. The S-band has a shorter wavelength of about 3.5 centimeters and is used for higher resolution imaging of the Earth's surface.