Sentinel 1 evolution: Sentinel-1C and -1D models

The paper provides an overview of the evolution of the Copernicus Sentinel-1 mission, which is part of the Copernicus European Earth Observation program. Following the successful launch and in-orbit Commissioning of Sentinel-1A in 2014 and Sentinel-1B in 2016, ESA is currently developing the Sentinel-1 C and D models. The paper addresses the expected improvements in system robustness and performance. In addition, it discusses the main characteristics of the Automatic Identification System (AIS) instrument to augment the SAR payload data for ship marine traffic applications and the Optical Communication Payload (OCP) for payload data downlink via inter-satellite laser-link with the European Data Relay System (EDRS). Finally, the design of Sentinel-1C and Sentinel-1D incorporates novel solutions that will make both satellites fully compliant with the latest Space Debris code-of-conduct and the required casualty risks at re-entry.