An Open Sentinel-1 Uncompressed SAR Dataset with FDBAQ Compression Performance Benchmarks

A dataset of uncompressed synthetic aperture radar (SAR) raw data has been acquired with Sentinel-1C and Sentinel-1D, providing, for the first time, complex raw data representative of the instrument signal prior to lossy onboard compression. Comprised of 65 Level-0 products and made openly available to the community, it enables a direct assessment of onboard processing algorithms with measurements unaffected by the flexible dynamic block adaptive quantization (FDBAQ) nominally applied by Sentinel-1. A detailed description of the data is presented together with an analysis of the achieved Sentinel-1 FDBAQ compression performance, obtained by emulating the compression/decompression process. The impact of the FDBAQ quantization on SAR radiometry and image quality is analyzed in both the single-look complex (SLC) and raw data domains. The released dataset and derived metrics are intended to establish a quantitative reference for evaluating future SAR compression schemes against the nominal Sentinel-1 FDBAQ implementation, supporting the development of onboard processing and compression-aware machine-learning algorithms.