DLR's Independent Verification of the Sentinel-1C System Calibration

Abstract

European Space Agency's (ESA) Sentinel-1C will be the third satellite of the Sentinel-1 mission. To be launched in late 2024, it will ensure seamless continuity of C-band SAR data for global monitoring of the Earth surface in the framework of the Copernicus program. In parallel to the commissioning of Sentinel-1C by ESA, an independent system calibration will be performed by DLR on behalf of ESA. Based on an efficient calibration strategy, this paper describes the different activities to be performed by DLR. Due to the stringent performance requirements of Sentinel-1, on behalf of ESA, the DLR SAR Calibration Center already performed a similarly organized independent end-to-end system calibration of S1A in 2014 and of S1B in 2016, relying on a separate dedicated suite of in-house analysis tools and the innovative and highly-stable reference ground targets deployed along DLR's SAR calibration field in Southern Germany. However, S1-C is not simply an exact rebuilt of its predecessors S1A/B but has implemented a series of hardware improvements for lessons learnt with the previous missions. These novel aspects and their impact on the calibration strategy will be discussed in detail in the presentation at the workshop. Launch for S1-C is currently foreseen for the end of November 2024 - this will allow us to present the latest on the final preparations for the DLR contribution to the S1-C in-orbit commissioning phase, including relevant results from the pre-launch rehearsal phase which is scheduled to take place in September/October 2024.