The recent radar imagery from the NASA-ISRO Synthetic Aperture Radar (NISAR) mission is providing unprecedented views of an Antarctic mountain and its surrounding glacier fractures, revealing details far beyond what conventional satellite photos can capture.
Unlike typical satellites that rely on visible light, the NISAR satellite uses radar technology. It emits microwave pulses toward Earth and analyzes the reflections to gather data continuously, regardless of daylight or weather conditions such as cloud cover.
Since July 20, 2026, the public has had access to NISAR’s data following nearly a year dedicated to calibrating instruments and refining the mission's data processing techniques. This has enabled scientists to receive constant updates of land and ice dynamics worldwide.
One compelling early image highlights Nunatak Zaterjavshijsja, a rocky mountain in East Antarctica surrounded by a glacier flowing toward the sea. Radar imaging reveals intricate fractures within the ice that are often invisible in traditional optical photos.
NISAR’s Radar Brings Antarctic Ice Structures Into View
This radar imagery of Nunatak Zaterjavshijsja was generated using data from NISAR’s L-band radar gathered during spacecraft testing in August 2025. The image displays the mountain encircled by fractured ice sheets, shaped by the glacier’s movement around the exposed rock.
As the glacier moves past, internal stresses cause deep cracks called crevasses. In the radar map, these crevasses stand out as distinct green lines, while smoother ice regions appear magenta. NASA credits signal analysis engineer Seongsu Jeong for producing this image. Jeong explained that radar reveals glacier dynamics invisible to optical methods.
“First, it’s a beautiful image, with rich details of features that provide insights to how the glacier is moving,” Jeong said. He also noted that: “because radar can often see through snow and deep into the ice, NISAR can observe fundamentally different properties of Antarctic ice than can be seen in optical imagery. With NISAR we’re seeing what’s hidden beneath the surface.”
The image’s colors indicate how radar waves interact with the environment. Magenta regions represent relatively smooth surfaces reflecting signals, while green areas indicate volume scattering occurring when waves penetrate snow or ice, or bounce off rough structures such as crevasse walls. White zones show a mix of these effects.
Innovative Radar Satellite Enhances Earth Monitoring
NISAR stands out among Earth observation missions by housing two radar instruments: the L-band radar and the S-band radar. It is the first satellite to offer both radar bands in free flight. Each band reveals unique details of Earth’s surface due to their differing wavelengths.
L-band radar’s longer wavelength enables penetration through dense forests, uncovering terrain beneath foliage. Meanwhile, S-band radar supplies data on vegetation structures, including leaf size and canopy organization.
According to NASA, NISAR has scanned nearly all terrestrial and icy regions globally twice every 12 days. Its observations cover diverse environments such as urban areas, farmlands, landslide-prone sites, earthquake zones, subsiding regions like Mexico City, and frozen Antarctic expanses.
Building a Comprehensive Record of Earth's Changes
The public availability of NISAR datasets initiates a vast global archive dedicated to monitoring planetary transformations. The satellite streams data totaling tens of terabytes daily as it continuously surveys wide segments of Earth.
The Indian Space Research Organisation’s Space Applications Centre in Ahmedabad manages S-band radar data distribution via the Bhoonidhi portal. Simultaneously, U.S. teams have been delivering calibrated L-band outputs since July 20, documenting data collected from June 17, 2026.
Alaska Satellite Facility Distributed Active Archive Center in Fairbanks advises that NASA radar products from NISAR are accessible to researchers and the public. Initial releases included approximately 25 example datasets in January, with thousands of calibrated products available since February.
NISAR’s observational coverage extends from near the South Pole up to 77.5 degrees north latitude, deeper than the Arctic Circle. As NASA and ISRO prepare to mark the first anniversary of the satellite’s July 30, 2025 launch from the Satish Dhawan Space Centre in India, the mission is compiling a detailed archive of Earth’s seasonal and long-term evolution.
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