The scene, acquired on November 29, 2025, with NISAR's L-band synthetic aperture radar instrument, spans the cities of New Orleans and Baton Rouge, the winding Mississippi River between them, nearby communities, and extensive mosaics of wetlands, farmlands, and forests.
Because the L-band radar uses microwaves with a wavelength of about 9 inches, or 24 centimeters, the signals pass through clouds that would obscure the view for optical sensors and return detailed information about the land surface below.
On the same day as the radar acquisition, optical images of the region from other satellites showed the area largely hidden under cloud layers, highlighting the advantage of radar observations for all-weather monitoring.
Mission scientists used the preliminary L-band measurements from NISAR to generate a color composite in which different hues correspond to distinct land cover types and structural characteristics on the ground.
In the image, portions of New Orleans appear in green tones where the radar echoes likely scatter from buildings oriented at multiple angles relative to the satellite's flight path, producing a complex backscatter signature.
Other parts of the city show up as magenta, especially where street grids run parallel to the satellite track, causing strong, bright reflections from building walls that send more of the radar signal directly back to the instrument.
The radar resolution is fine enough to clearly pick out the Lake Pontchartrain Causeway just to the right of center, where the twin bridges stretch nearly 24 miles, or about 39 kilometers, making them the longest continuous bridge structure over open water in the world.
West of the Mississippi River, bright green patches outline healthy forested areas where tree canopies and understorey vegetation scatter the microwaves in many directions before some of the energy returns to the satellite.
By contrast, the Maurepas Swamp region, located directly west of Lake Pontchartrain and the smaller Lake Maurepas, displays a mottled pattern of yellow and magenta that indicates thinning tree stands and changes within this wetland forest ecosystem.
On both sides of the Mississippi, the radar view resolves agricultural parcels of varying shapes and sizes, with darker tones suggesting fallow fields and bright magenta pixels marking areas where tall crops may be present.
This single image illustrates how L-band SAR can discriminate between low-lying vegetation, taller trees, engineered infrastructure, and urban development, providing key information for monitoring forest and wetland health and for following crop conditions through the growing season.
As NISAR completes its post-launch commissioning, the project is preparing to release thousands of data products in late February so that researchers, resource managers, and other users can begin routine analysis of the global L-band observations.
To help the community get ready for this larger data flow, the mission has already distributed a smaller set of sample products that demonstrate file formats and processing approaches for upcoming NISAR datasets.
The Alaska Satellite Facility Distributed Active Archive Center in Fairbanks, Alaska, will host and distribute NISAR L-band radar data products to users worldwide as part of NASA's network of synthetic aperture radar archives.
Beyond ecosystem and agricultural studies, mission planners expect NISAR data to support disaster response, infrastructure inspection, and other applications where frequent, cloud-penetrating, day-or-night imaging can provide actionable information to decision makers.
NISAR is a joint Earth-observing mission developed by NASA and the Indian Space Research Organisation, with the satellite designed to routinely monitor changes on Earth's land and ice surfaces over the life of the mission.
The spacecraft launched on July 30 from the Satish Dhawan Space Centre on the southeastern coast of India and now operates in orbit, collecting data with a large, drum-shaped radar reflector that spans about 39 feet, or 12 meters, in diameter.
NASA's Jet Propulsion Laboratory in Southern California leads the United States contribution to NISAR for the agency, manages the U.S. science team, and built the L-band SAR instrument and its deployable antenna reflector.
ISRO provided the spacecraft bus that carries the payload and contributed an S-band SAR operating at a wavelength of about 4 inches, or 10 centimeters, which complements the L-band system at a shorter radar wavelength.
NISAR is the first satellite mission to fly two synthetic aperture radar instruments at different wavelengths on the same platform, enabling it to track a wide range of processes affecting Earth's land and ice surfaces.
Operating in this dual-frequency mode, the satellite will revisit and map the planet's land and ice areas twice every 12 days, yielding dense time series of radar observations that can reveal subtle changes and trends over time.
By combining the sensitivity of L-band and S-band radar to different target sizes and structures, mission scientists can better distinguish between surface roughness, vegetation structure, and ground deformation in their analyses.
Over its planned lifetime, NISAR's regular, cloud-independent imaging is expected to advance understanding of hazards such as earthquakes, landslides, and floods, as well as long-term processes tied to climate, agriculture, and ecosystem dynamics.
Related Links
NASA-ISRO Synthetic Aperture Radar Mission
Earth Observation News - Suppiliers, Technology and Application
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