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NISAR L-band SAR

NISAR L-Band SAR Viewer Online

View NASA-ISRO NISAR radar imagery in your browser. Its 24 cm wavelength reaches through vegetation canopy that C-band radar only images the top of.

Quick answer — what NISAR L-band gives you

NISAR is a NASA-ISRO radar satellite launched 30 July 2025, carrying an L-band SAR at about 24 cm wavelength. The public product is L2 GCOV — terrain-corrected gamma-0 backscatter in HH and HV on a 10 m grid, distributed free by the Alaska Satellite Facility, with a 12-day repeat cycle (about 6 days average revisit combining ascending and descending passes) and an archive starting 16 June 2026. The long wavelength is what matters: it sees flooding beneath tall canopy and woody structure inside forests that Sentinel-1 C-band cannot reach. Calibration is provisional, so backscatter values are indicative rather than measured. NISAR layers require a plan that includes them (see Pricing).

Sees Under Canopy

A 24 cm wave passes through the leaf layer and interacts with branches, trunks, and the ground — where C-band stops at the canopy surface.

Flooding Beneath Trees

Standing water under a closed canopy produces a strong double-bounce return at L-band. At C-band, flooded and dry forest can look nearly identical.

12-Day Repeat

Same-geometry pairs come every 12 days; combining ascending and descending passes gives about a 6-day average revisit for any look.

NISAR or Sentinel-1?

They are not substitutes. Sentinel-1 has acquired since 2014 and reaches a same-geometry repeat pair about twice as fast, so it remains the better first look for open water, urban change, and anything needing history. NISAR answers a question C-band structurally cannot: what is underneath the vegetation.

Read the full comparison, with the measured numbers

How It Works

1

Navigate to Your Area

Pan and zoom to the area you want to look at.

2

Select NISAR

Choose NISAR as the satellite source and search a date range. The public archive begins 16 June 2026.

3

Add to Map

The area you selected is converted before it can be drawn, which takes about 30 seconds. Viewing the same area again is served from cache.

4

Compare

Switch between HH and HV, or between the searched area and the whole scene at 80 m.

Frequently Asked Questions

What is NISAR?▼
NISAR is a joint NASA-ISRO radar satellite launched on 30 July 2025 from the Satish Dhawan Space Centre. It flies at 747 km in a 98.4° sun-synchronous orbit and carries an L-band radar (~24 cm wavelength) built by NASA and an S-band radar (~9.4 cm) built by ISRO. NASA states it observes every 12 days from both ascending and descending orbits, giving an average revisit of about 6 days.
How is L-band different from Sentinel-1 C-band?▼
Wavelength. NISAR L-band is about 24 cm against Sentinel-1 C-band at 5.55 cm, a ratio of roughly four. Radar interacts most strongly with objects comparable to its wavelength, so C-band scatters off leaves and images the canopy surface, while L-band passes through that layer to branches, trunks, and the ground. The clearest practical case is flooding beneath a closed canopy, which C-band largely cannot see.
Which NISAR product does this viewer show?▼
The L2 GCOV product (Geocoded Polarimetric Covariance) distributed by the Alaska Satellite Facility. NASA describes it as terrain-corrected gamma-0 backscatter that can be used the same way as Normalized Radar Backscatter or Radiometrically Terrain Corrected products, so it drops into an existing Sentinel-1 RTC workflow. It carries no interferometric phase, so coherence-based work needs a different NISAR product.
Which polarizations does NISAR provide?▼
The published dual-pol horizontal granules carry HH and HV — horizontal transmit — not the VV and VH that Sentinel-1 uses over land. Transmit polarization is not interchangeable, so Sentinel-1 polarization intuitions do not carry across unchanged. The cross-polarized channel (HV here) is the one sensitive to volume scattering from vegetation and debris.
Is NISAR data calibrated?▼
Not fully. The collections published so far are labelled beta and provisional, and no separately published calibrated GCOV collection exists yet. Relative comparisons within a scene, and change between two scenes of the same collection, are the defensible uses today; absolute gamma-0 values quoted as measurements are not. Layers here are labelled as provisionally calibrated.
Why does a NISAR scene take about 30 seconds to appear?▼
Unlike the other sources, NISAR has no tiled imagery in the catalog — a granule is several gigabytes of HDF5. The area you select is converted on demand before it can be drawn. Viewing the same area again is served from cache and is free. A whole-scene view uses the product own 80 m grid rather than a decimated version of the 10 m grid.
How far back does the NISAR archive go?▼
The earliest public GCOV acquisition is 16 June 2026. For anything before that date NISAR cannot contribute, and Sentinel-1 — which has acquired since 2014 — is the source with history.

Related Resources

NISAR vs Sentinel-1

When wavelength decides the answer

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Sentinel-1 SAR Viewer

C-band radar, 2014 to present

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Data Sources

Every source, licence and citation

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SAR vs Optical

Which sensor answers which question

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Why SAR Sees Through Clouds

The physics of radar imaging

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Glossary

L-band, GCOV, gamma-0, coherence

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Start Viewing NISAR L-Band Data

Search and display L-band radar scenes in your browser. NISAR is a plan-gated layer; see Pricing for which plans include it.

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