PRODUCTS

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Note: this section provides a concise description of the products provided by the GFM.
For a more comprehensive documentation the reader is referred to the GFM Products Description Document.


The GFM makes available a full set of NRT flood mapping-related products as listed below:

Products Data format
1. S-1 Observed Flood Extent Flooded areas mapped as the difference between S-1 observed water extent
and the reference water mask.
raster (Geotiff) and vector(shapefile)
2. S-1 Observed Water Extent Open and calm water mapped using S-1 SAR backscatter intensity. raster (Geotiff) and vector(shapefile)
3. S-1 Reference Water Mask Normal (i.e. permanent, seasonal) water mapped using S-1 SAR backscatter intensity. raster (Geotiff) and vector(shapefile)
4. Exclusion Mask Unclassified areas raster (Geotiff)
5. Uncertainty Values Estimated uncertainty of flood mapping, for all areas outside exclusion mask raster (Geotiff)
6. Advisory Flags Flags indicating potential reduced quality of flood mapping, due to prevailing

environmental conditions (e.g. wind, ice, snow, dry soil), or degraded input data quality due
to signal interference from other SAR missions (e.g. Radarsat)

raster (Geotiff)
7. Sentinel-1 Metadata Information on the acquisition parameters of the S-1 data used KML
8. Sentinel-1 Footprint Image boundaries of the S-1 data used KML
9. Sentinel-1 Schedule Next scheduled S-1 data acquisition KML
10. Affected Population Number of people in flooded areas, mapped by a spatial overlay of observed flood extent
and gridded population
raster (Geotiff)
11. Affected Land Cover Land cover type flooded raster (Geotiff)


The key specification of the products are provided in the table below

Input satellite data
Satellite sensor S-1 - Synthetic Aperture Radar (SAR)
Acquisition mode Interferometric Wide Swath (IW)
Data product Level-1 - Ground Range Detected (GRD)
Spatial sampling 20 x 22 metres
Global revisit frequency Europe: ~1-3 days. Rest of the world: ~3-14 days, depending on location
SAR polarisation scheme VV + VH
GENERAL GFM PRODUCT SPECIFICATIONS
Geographic coverage Global
Pixel size 20 metres
Timeliness <8 hours after S-1 image acquisition.
Thematic accuracy Target threshold of >70-80%, based on the Critical Success Index