Sentinel-1 Level-1 Ground Range Detected (GRD) products are part of “The International Charter Space and Major Disasters” (Charter) activations data collections.
Today, the Sentinel-1 GRD products are pre-processed to produce a backscatter screening product, using the co-polarization band (e.g. VV or HH), made available in the Charter Processing Platform Trial on the GEP.
Below an example of such screening products for the Charter activation [Act-598/Call-688] concerning the floods in Mozambique in March 2019 where the tropical cyclone Idai has brought torrential rain and flash flooding to parts of Mozambique. Over 100 people were killed and over 500,000 were displaced.
In the context of enriching the future Charter activations in the Charter Processing Platform, Terradue is preparing new and advanced processing services.
The upcoming screening processing service for Sentinel-1 GRD generates an RGB composite combining both polarizations (for dual polarization products). These RGB composites are very useful for having an overview of the flood extent.
Furthermore, e.g. in the case of the floods in Mozambique in March 2019, the extent of the flooded area covered an area larger than a single Sentinel-1 GRD acquisition. To address these cases and to ease the visual interpretation, the Sentinel-1 GRD RGB composite service may take up to two consecutive acquisitions that are “stitched” before generating the RGB composite.
Below the screening product generated by such service for the Mozambique Beira floods where two consecutive scenes were used to cover the flooded area. The dark blue pixels on land show the damaged area.
Then, if combined with a pre-flood screening product, one can see the changes using the slider bar available on the platform:
More to come!