Mission Overview
NISAR Mission, or the NASA–ISRO Synthetic Aperture Radar Mission, is a joint Earth-observation satellite developed by the Indian Space Research Organisation and the United States’ National Aeronautics and Space Administration.
It is the first satellite mission to carry two different radar systems:
- L-band Synthetic Aperture Radar, developed by NASA
- S-band Synthetic Aperture Radar, developed by ISRO
NISAR was launched aboard India’s GSLV-F16 from the Satish Dhawan Space Centre, Sriharikota, on 30 July 2025.
The satellite is designed to observe changes occurring on the Earth’s land, vegetation and ice surfaces with very high precision.
Technology and Working
NISAR uses Synthetic Aperture Radar, which sends microwave signals towards the Earth and records the signals reflected from the surface.
Unlike optical satellites, radar satellites can collect data:
- during both day and night;
- through clouds, smoke and light rainfall;
- under different weather conditions.
The L-band radar has a longer wavelength and can penetrate forest canopies to study vegetation, biomass and ground deformation.
The S-band radar has a shorter wavelength and is useful for studying crops, soil conditions, surface changes and certain types of vegetation.
The satellite carries a large 12-metre deployable mesh antenna reflector to transmit and receive radar signals.
It operates in a near-polar, Sun-synchronous orbit and revisits most locations on Earth at regular intervals. Comparing repeated observations allows scientists to detect small changes in the Earth’s surface.
Major Objectives
NISAR is designed to study three broad processes.
Changes in ecosystems
It measures forests, wetlands, agricultural areas and biomass. The data can help assess deforestation, crop conditions and changes in carbon storage.
Movement of the Earth’s surface
It can detect surface deformation caused by:
- earthquakes;
- volcanic activity;
- landslides;
- groundwater extraction;
- land subsidence.
Changes in ice
The mission monitors glaciers, ice sheets and sea ice. This can improve understanding of glacier movement, ice loss and sea-level rise.
The mission can detect some surface movements measured in centimetres and, under suitable conditions, even smaller long-term deformation.
Applications
NISAR data can support:
- earthquake and landslide assessment;
- flood mapping;
- agricultural monitoring;
- forest and biomass estimation;
- wetland observation;
- glacier and ice-sheet studies;
- groundwater and land-subsidence monitoring;
- coastal and environmental management.
Its ability to observe large areas repeatedly makes it useful for disaster preparedness and post-disaster assessment.
The mission will generate large quantities of radar data. Much of its scientific information is intended to be made openly available, allowing researchers and public institutions across the world to use it.
Importance of the Mission
NISAR represents one of the most advanced scientific collaborations between India and the United States.
India contributed:
- the S-band radar;
- the spacecraft bus;
- the launch vehicle;
- satellite assembly and testing;
- launch and mission operations.
NASA contributed:
- the L-band radar;
- the large antenna reflector;
- high-capacity data and communication systems;
- several supporting engineering components.
The mission strengthens India’s capabilities in radar imaging, disaster management and environmental monitoring. It also demonstrates a shift in India–U.S. space relations from carrying individual instruments to jointly designing and operating a major satellite mission.
Conclusion
NISAR combines advanced radar technology with international scientific cooperation to monitor the Earth’s changing surface. Its observations can improve understanding of natural disasters, ecosystems, glaciers and climate-related changes while supporting evidence-based planning and disaster resilience.
