TAGS

sentinel 1

grd

ground range detected

Sentinel-1 GRD in Cloud Optimized GeoTIFF format

Sentinel-1 GRD (Ground Range Detected) is one of the most popular Copernicus data collections served by the CREODIAS platform. Every month GRD products are accessed more than 3 million times by CREODIAS users, making it the second most processed data collection, with Sentinel-2 being on the top.

Due to its low dependence on atmospheric conditions SAR data, and especially GRD Level 1 products have various uses including marine monitoring (ice shelf changes and iceberg tracking, sea vessels monitoring), land monitoring (forestry and agriculture analysis including agriculture policy checks, urban deformation mapping) and plays critical role emergency monitoring enabling detection and analysis of catastrophic events - floods, earthquakes, landslides, volcanos and other disasters resulting in land deformation.

However current file formats used in GRD products distributed by the Copernicus data processing requires transferring a lot of data to process even small parts of the scene. Typical request to Sentinel-1 data requires twice as much data to be transferred comparing to Sentinel-2 products.

To improve the performance of Sentinel-1 processing the CREODIAS platform offers additional collection providing GRD data files in the new, optimized format - Cloud Optimized GeoTIFF (COG). This new data format enables much more efficient processing due to layered and tiled structure of data. Low resolution information can be extracted quickly with very little data transferred from the repository to client application and specific parts of scene can be accessed immediately. More information on COG can be found here: https://www.cogeo.org/.

The COG format is currently supported by major EO data analysis tools includig GDAL, GeoServer, Orfeo Toolbox, QGIS and many more.

The CROEDIAS platform offers a 30 day rolling archive of Sentinel-1 GRD COG products with new data added continously along standard GRD products delivered by ESA. The new products are stored in a dedicated bucket and folder in the CREODIAS Data Repository and indexed to enable access through our search GUI and API (https://finder.creodias.eu).

The name of new products is created by appending "_COG" to the original GRD product name.

Example: S1A_EW_GRDM_1SDH_20190201T235821_20190201T235906_025743_02DCAC_7076 *_COG*.SAFE

COG collection is located under following repository branch: /Sentinel-1-COG/SAR/GRD-COG/