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The World’s Most Advanced Radar Satellite Begins Operations
The successful launch of the NASA-ISRO Synthetic Aperture Radar (NISAR) mission in July 2025 marked a major milestone for the Earth Observation community. Developed jointly by NASA and the Indian Space Research Organisation (ISRO), NISAR combines L-band and S-band Synthetic Aperture Radar (SAR) instruments on a single platform, making it the first satellite of its kind. [isro.gov.in], [isro.gov.in]
Unlike optical satellites, radar systems actively transmit energy and measure the returning signal. This allows observations to be collected day or night and through cloud cover, making radar indispensable for monitoring dynamic environmental processes. NISAR is designed to map nearly all of Earth’s land and ice surfaces every 12 days, providing unprecedented insight into environmental change. [isro.gov.in], [science.nasa.gov]
Why Dual-Frequency Radar Is Important
Most radar missions operate at a single frequency. NISAR carries both:
- L-band SAR (24 cm wavelength)
- S-band SAR (9.4 cm wavelength)
The longer L-band wavelength can penetrate vegetation canopies and provide information about forest structure and biomass, while S-band observations capture complementary surface characteristics. Together, they provide a richer understanding of ecosystems, surface deformation, and environmental change. [isro.gov.in], [science.nasa.gov]
Applications Across the Geospatial Sector
Natural Hazards
NISAR can measure subtle ground movements associated with earthquakes, volcanoes and landslides. Scientists expect the mission to improve understanding of how Earth’s surface changes before and after major events. [isro.gov.in], [science.nasa.gov]
Forest Monitoring
Radar’s ability to penetrate vegetation means NISAR will play an important role in biomass estimation and ecosystem monitoring, complementing missions such as ESA’s Biomass satellite. [isro.gov.in], [science.nasa.gov]
Agriculture
Regular observations can support crop monitoring, soil moisture assessment and food security initiatives. [isro.gov.in], [science.nasa.gov]
Cryosphere Research
The mission will provide valuable information about glaciers, ice sheets and polar environments, helping scientists understand the impacts of climate change. [isro.gov.in], [science.nasa.gov]
A New Era for Open Radar Data
Perhaps most importantly, NISAR follows the growing trend towards openly accessible Earth Observation data. The mission’s datasets are being distributed freely to users worldwide, further lowering barriers to radar analysis and encouraging innovation across academia, government and industry. [science.nasa.gov], [science.nasa.gov]