Sentinel-1 first generation status, past and future

The Copernicus Programme is a joint European initiative developed by the European Commission (EC) and the European Space Agency (ESA) to provide accurate, up-todate, and comprehensive Earth observation data for environmental monitoring, climate change analysis, disaster management, and security. The Copernicus program comprises a series of dedicated satellite missions i.e., the Sentinels spanning a wide range of the electromagnetic spectrum with different sensing techniques. Sentinel-1 [1] is the radar imaging component of Copernicus. It is a two-satellites constellation placed in the same orbit and spaced 180 degrees apart. The Sentinels are providing systematically data to the Copernicus service component and scientific users. The Copernicus operational services are covering key operational applications tailored to support the definition and monitoring of European policies such as: - Observation of the marine environment and sea-ice monitoring - Surveillance of maritime transport zones - Land surface mapping, e.g., vegetation cover and surface deformation, - Polar environment monitoring (e.g., ice shelves and glaciers) - Climate Change - Emergency Response and Management The Sentinel-1 first generation comprises four satellite units developed in two batches. The first two (A and B) have been already launched and two recurrent (C&D) ones planned for launch ensuring continuity of measurement throughout the 2020's. Sentinel-1C and D will overlap with other Copernicus SAR mission in development like ROSE-L [2] and the Sentinel-1 Next Generation [3]. In this paper we discuss the status and evolution of the Sentinel-1 first generation.