Sentinel-1: Implementation of a Radar Observatory

The ESA Sentinels constitute the first series of operational satellites responding to the Earth Observation needs of the EU-ESA Global Monitoring for Environment and Security (GMES) programme. The GMES space component relies on existing and planned space assets as well as on new complementary developments by ESA. In contrast to SAR systems already existing in C-band like ASAR/ENVISAT or RADARSAT-2, high demands on the radiometric accuracy are made for Sentinel-1. This paper provides an overview of the main features of GMES Sentinel-1 System, a C-band Synthetic Aperture Radar Observatory for Earth Observation. The main system requirements are presented as drivers for the design of system, satellite and operations. The major design challenges as well as the most critical development aspects are outlined, mainly focusing on the Space Segment components.