Geocoding Sentinel-1 GRD Products
These recipes are designed to help users geocode Sentinel-1 Ground Range Detected (GRD) data to a map projection. Geocoding is an important step because it allows SAR data to be compared or integrated with other types of data (satellite images, maps, etc.) and used for GIS analysis.
Sentinel-1 GRDs are georeferenced to WGS 84 geographic coordinates, and most GIS software packages will recognize the spatial reference of a GRD and project it appropriately on-the-fly.
To perform more complex GIS analysis, or to ensure that the image displays in the correct orientation when viewed outside of a GIS environment, it should be transformed from SAR geometry to a projected coordinate system. In SAR applications, this process is referred to as Geocoding.
We have provided data recipes for geocoding using GDAL, ArcGIS and QGIS platforms. While the different processing platforms may return slightly different results, one approach is not necessarily better than the others. We recommend using a consistent approach for any given project, based on the project goals and the user’s preferred working environment.