Starting July 20, the public can access data from the two powerful radar instruments on board the NISAR (NASA-ISRO Synthetic Aperture Radar) satellite. Teams in the United States and India will release files processed from the satellite’s L-band and S-band radars on an ongoing basis, helping researchers and other users track the movement of Earth’s land and ice masses, monitor changes in ecosystems such as forests and wetlands, and respond to natural hazards such as landslides and earthquakes.

The launch comes as NASA and ISRO (Indian Space Research Organization) prepare to celebrate the first anniversary of the launch of NISAR on July 30, 2025 from India’s Satish Dhawan Space Center. Since then, the mission’s science and engineering teams have been busy calibrating instruments, refining algorithms, and monitoring nearly all of the planet’s land and ice-covered surfaces twice every 12 days. Along the way, the team has captured scenes from around the world: urban streets, agricultural fields, landslides, earthquakes and land subsidence in Mexico City.

One of the first images released on Tuesday revealed in fine detail the arid, fractured surface of an Antarctic landscape. In a fusion of science and chance, it also looks like something else entirely: a hummingbird.

Despite its otherworldly quality, the Antarctic image shows a very real geographic feature called Nunatak Zaterjavshijsja, a mountaintop in East Antarctica, jutting out in the middle of an ice stream flowing northeast toward the ocean. As the moving glacier passes the obstruction, the mountain’s topography causes stresses in the ice, severely fracturing the surrounding surfaces with deep cracks, called crevasses, which show up as sharp green lines in the image.

“First, it’s a beautiful image, with rich detail of features that provide information about how the glacier moves. Then, because radar can often see through snow and into the depths of ice, NISAR can observe fundamentally different properties of Antarctic ice than can be seen in optical images,” said Seongsu Jeong, the signals analysis engineer who produced the image at NASA’s Jet Propulsion Laboratory in Southern California. “With NISAR we are seeing what lies beneath the surface.”

Generated from measurements that NISAR’s L-band instrument collected in August 2025, while mission teams from the United States and India were testing the satellite’s systems, the “hummingbird” exemplifies one of the young mission’s hallmarks: intricately detailed images that are both informative and eye-catching.

The colors show differences in the way polarized microwave signals, vibrating in different directions, interact with and reflect off the ice. Over Antarctica, NISAR transmits horizontally polarized radar waves toward Earth. The orientation of the returning signals (whether horizontal, vertical, or both) provides clues about the object or surface that reflected them.

Signals returning with a horizontal polarization probably bounced off a more regular surface, such as smooth ice. Those signals appear magenta in the image. Signals returning with vertical polarization may have been refracted by partially penetrating snow and ice or scattered at different angles by reflecting off irregular surfaces, such as crevice faces. These observations, called volume spread, are shown in green.

White represents areas where the magenta and green signals are strongly scattered, a possible indication that there is an equal combination of surface and volume scattering.

The same scene seen with optical light is almost completely white from ice and snow. Slight shadows and ripples indicate the presence of the mountain top, and textures in the surrounding area suggest that the ice is not completely smooth.

The NISAR satellite is the first free-flying space mission to have two radar instruments: an L-band system and an S-band system. The systems are complementary due to their different wavelengths. For example, the longer wave L band can pass through tree canopies and image the ground below. Meanwhile, depending on the size of the leaves, the S-band can collect observations from those canopies.

The Indian science team, based at ISRO’s Space Applications Center in Ahmedabad, recently started publishing S-band data through the Bhoonidhi portal.

On July 20, the US portion of the mission began releasing continuously calibrated products for all L-band measurements collected since June 17. By the end of the year, the team hopes to have published all the data previously acquired during scientific operations. The NISAR project science team previously had two limited releases of L-band data, the first in January of approximately 25 sample products and a release in February of thousands of precalibrated products.

As with previous versions, data users will be able to download the latest files at the Alaska Satellite Facility’s Distributed Active Archive Center in Fairbanks, which hosts and distributes all of NASA’s synthetic aperture radar data.

The scientific data output of the NISAR mission is enormous, on the order of tens of terabytes per day, due to the satellite’s frequent coverage of almost all land and icy surfaces on Earth. Explore from a few degrees from the South Pole in Antarctica to 77.5 degrees north latitude, above the Arctic Circle.

Managed by Caltech, JPL leads the US component of the project and provided the satellite’s L-band SAR and antenna reflector. ISRO provided the spacecraft bus and its S-band SAR.

The NISAR satellite is the first to carry two SAR instruments at different wavelengths, collecting data using the spacecraft’s giant drum-shaped reflector, which measures 39 feet (12 meters) across, the largest radar antenna reflector NASA has ever sent into space.

For more information about NISAR, visit:

https://science.nasa.gov/mission/nisar/

Media contacts

Andrew Wang / Andrew Bueno
Jet Propulsion Laboratory, Pasadena, California.
626-379-6874 / 818-393-2433
andrew.wang@jpl.nasa.gov / andrew.c.good@jpl.nasa.gov

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