Available with Image Analyst license.
A Sentinel-1 (S1) single look complex (SLC) synthetic aperture radar (SAR) image must be processed before it can be used for visualization or analysis. Issues that need to be addressed include updating orbit data, merging bursts, removing thermal noise, calibrating to retrieve a meaningful backscatter value, mitigating speckle, removing radiometric and geometric distortions, and rendering images with a large value range.
The Synthetic Aperture Radar toolset, in the Image Analyst toolbox, contains tools you can use to generate calibrated, terrain-corrected, analysis-ready imagery data. The tools described in the following table are used to generate analysis-ready S1 SLC data, as outlined in the diagram below.
| Tool | Description |
|---|---|
Downloads the updated orbit files for Sentinel-1 synthetic aperture radar (SAR) data. | |
Updates the orbital information in the Sentinel-1 synthetic aperture radar (SAR) data using a more accurate orbit state vector (OSV) file. | |
Converts the scaling of the input synthetic aperture radar (SAR) data between amplitude and intensity, between linear and decibels (dB), and between complex and intensity. | |
Corrects backscatter disturbances caused by thermal noise in the input synthetic aperture radar (SAR) data, resulting in a more seamless image. | |
Converts the input synthetic aperture radar (SAR) reflectivity into physical units of normalized backscatter by normalizing the reflectivity using a reference plane. | |
Merges the multiple bursts from the input Sentinel-1 Single Look Complex (SLC) synthetic aperture radar (SAR) data and outputs a single, seamless subswath raster. | |
Averages the input synthetic aperture radar (SAR) data by looks in range and azimuth to approximate square pixels, mitigates speckle, and reduces SAR tool processing time. | |
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Corrects the input synthetic aperture radar (SAR) data for radiometric distortions due to topography. | |
Corrects the input synthetic aperture radar (SAR) data for speckle, which is a result of coherent illumination that resembles a grainy or salt and pepper effect. | |
Orthorectifies the input synthetic aperture radar (SAR) data using a range-Doppler backgeocoding algorithm. |
Processing considerations
Supported S1 SLC modes are Interferometric Wide Swath (IW), Extra Wide Swath (EW), and Stripmap (SM). The Deburst tool is only needed for IW and EW modes that are acquired using the Terrain Observation by Progressive Scan (TOPS) imaging technique. For S1 SLC Stripmap (SM), omit the Deburst tool from the workflow.
When you download and apply the orbit files, consider the type of orbit state vectors (OSVs) you'll use. The following types of OSVs are available for the Sentinel-1 product:
- Predicted—Provided with the Sentinel-1 Level 1 ground range detected (GRD) and SLC auxiliary products
- Restituted—Available through the European Space Agency (ESA) within three hours of image acquisition
- Precise—Available through ESA within three weeks of image acquisition