A new radar eye in the sky can detect Earth's movements within fractions of an inch
A collaborative mission between NASA and ISRO is preparing to map our changing planet. By peering through clouds and dense vegetation, this advanced satellite will monitor everything from melting glaciers to volcanic ground deformation, providing a high-precision look at the global vital signs we can no longer afford to ignore.
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission utilizes a dual-frequency radar system to capture unprecedented detail of Earth's surface. The satellite carries an L-band instrument, featuring a 24 cm wavelength, and an S-band instrument with a 9.4 cm wavelength. This combination allows the mission to penetrate cloud cover and darkness, even during polar winters. While the L-band is capable of seeing through snow to track underlying ice motion, the S-band is specifically sensitive to snow moisture, which serves as a critical indicator of melting processes.
Orbiting at an altitude of 747 km with a 98.4° inclination, NISAR is designed to observe nearly all of the planet's land and ice-covered regions. The mission follows a 12-day repeat cycle, capturing data from both ascending and descending orbits. This frequency results in an average revisit time of approximately every 6 days throughout its planned three-year baseline mission. Such regular sampling is vital for tracking the cryosphere, particularly the movement of ice sheets in Antarctica and Greenland.
The mission's scientific importance lies in its ability to monitor subtle surface deformations and environmental shifts. Researchers will use the data to study deforestation, groundwater movement, sea level variation, and the stability of ice shelves. By observing how saltwater interacts with ice sheets sitting below sea level, scientists hope to reduce the significant uncertainties currently surrounding sea level rise projections. All resulting data and products will be made available through free and open access via the Alaska Satellite Facility and Bhoonidhi.
Source: NISAR: Tracking Earth’s Changes From Space (Mission Overview)
