NISAR

NISAR (NASA-ISRO Synthetic Aperture Radar) is a joint Earth-observing satellite mission developed by the National Aeronautics and Space Administration (NASA) and the Indian Space Research Organisation (ISRO). It is scheduled to launch in June 2025.

Its aim is to measure changes in terrestrial ecosystems, ice sheets, glaciers, sea ice, and crust deformation.


Background & Collaboration


The partnership between NASA and ISRO for the NISAR mission was formalized on September 30, 2014. As part of this collaboration:

  • NASA provides the L-band radar, high-rate communication subsystem, GPS receivers, and a payload data subsystem.
  • ISRO contributes to the S-band radar, satellite bus, and launch services.

The satellite will be launched aboard ISRO’s Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II) from the Satish Dhawan Space Centre, Sriharikota.



Key Technologies & Applications


NISAR Mission


NISAR will be the first satellite mission to operate dual-frequency radar systems, using:

  • L-band radar (by NASA)
  • S-band radar (by ISRO)

It will be the first satellite mission to collect radar data in two microwave bandwidth regions, allowing it to observe a wide range of Earth processes.

NISAR employs a sophisticated Synthetic Aperture Radar (SAR) technique. 

SAR can generate high-resolution images of the Earth's surface regardless of weather conditions or time of day. Its 'SweepSAR' technology allows for a large coverage area with high resolution.

The mission aims to map the entire globe every 12 days, providing consistent and detailed data on:

  • Ecosystems: Biomass, forest cover changes, and wetlands.
  • Ice Mass: Understanding the growth and retreat of glaciers and ice sheets, contributing to sea-level rise.
  • Dynamic Surfaces: Movements of the Earth's crust related to earthquakes, volcanoes, and landslides.
  • Natural Hazards: Improved monitoring and assessment of various disasters.
  • Groundwater: Providing insights into water resources.

The data collected will help researchers understand the capture and release of carbon in both ecosystem types and will be made freely available to the public.

The planned mission duration is three years, with the satellite orbiting Earth in a sun-synchronous orbit at an altitude of 747 km.


Conclusion


The NISAR mission is a landmark in international collaboration and radar remote sensing. It is poised to transform our understanding of Earth’s systems through frequent, high-resolution global observations.

Its comprehensive data will support climate science, natural resource management, and disaster resilience for years to come.