ESA SNAP — The Complete Guide: Free Satellite Image Processing and Ground Subsidence Mapping
ESA SNAP is the European Space Agency’s workbench for processing satellite data, above all Sentinel data, which can be downloaded freely through the Copernicus programme. It bundles separate toolboxes for radar, optical imagery and ocean and land data, and runs on Windows, macOS and Linux.
ESA SNAP
European Space Agency
The European Space Agency’s satellite data toolbox: Sentinel imagery, radar interferometry for ground subsidence, vegetation indices and flood mapping.
Get it from the vendorWhat you get
- Radar (SAR) processing — calibration, terrain correction and speckle filtering of Sentinel-1 images.
- Interferometry (InSAR) — producing interferograms and displacement maps to detect ground subsidence.
- Optical processing — vegetation indices, land-cover classification and atmospheric correction for Sentinel-2.
- Graph Builder — chaining processing steps into one workflow and running it on many images.
- Command line and Python — automating workflows without the graphical interface.
What to know before you start
Satellite scenes are large, and SNAP needs a computer with plenty of memory. The InSAR learning curve is steep: start with ESA’s official tutorials on a single image pair before you analyse a long time series. Results export to GeoTIFF and continue into a GIS program for maps and reports.
Related tools
For remote-sensing processing with additional algorithms — Orfeo ToolBox. For display and combination with other layers — QGIS. For format conversion and batch processing — GDAL.
Orfeo ToolBox (OTB)
CNES and OTB contributors (OSGeo)
A remote-sensing image processing library with dozens of command-line applications and a QGIS plugin for satellite and aerial imagery.
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QGIS
QGIS.org
Open-source GIS for spatial analysis, layer work and map production.
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GDAL
OSGeo
Command-line tools and a library to convert, reproject, clip and process geodata — DEMs, GeoTIFF, Shapefile and more.
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GRASS GIS
OSGeo
GIS with strong raster and terrain analysis — catchments, slope, visibility and elevation models.
Get it from the vendorThe bottom line
SNAP is the main free tool for turning Sentinel data into engineering information, from subsidence under infrastructure to flood mapping. Open source and completely free, including for commercial use.