PRODUCTS
From MyDewetra World
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 |
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 |
