Processing Multiple NISAR RSLC Level-1 Images for High-Resolution Stacking (~2–3 m) in Radar Geometry

[azizi112]

Hello,

I would like guidance on processing NISAR Level-1 RSLC data.

I am working on processing multiple RSLC images acquired from the same orbit, similar to how multiple ALOS PALSAR FBS SLC images are processed. My goal is to stack several images to reduce noise while preserving the highest possible native resolution (~2–3 meters).

I am looking for a clear workflow that includes:

Radiometric calibration (Sigma0)

Doppler handling

Basic filtering (such as refined Lee)

Accurate coregistration of multiple RSLC images in radar geometry (Range/Azimuth)

My main questions are:

How to correctly coregister multiple RSLC images without performing full geocoding, so that each pixel aligns precisely with its corresponding pixel.

How to apply terrain correction while maintaining the original spatial resolution.

How to retain or achieve an effective resolution close to 2–3 meters after stacking multiple RSLC images.

Which tools or workflows in ISCE3 or OpenSARLab are recommended for this type of processing.

My goal is to perform the full analysis in radar geometry first, then apply geocoding only to a small area of interest afterward.

Any guidance, references, or examples would be highly appreciated.

Thank you.

Nafea Azizi

[ASF - bhauer]

Hello Nafea,
Have you explored the Level 2 geocoded GSLC product, which is derived from the RSLC product? Information on this can be found in the Data Products section of the NISAR Data User Guide.

Refer to this Earthdata Forum post to see code for converting GSLC DN values to a different radar backscatter coefficient.