GMES SENTINEL-1 Satellite and C-SAR Instrument
Panetti, Aniceto¹; Rostan, Friedhelm²; L'Abbate, Michelangelo¹; Bruno, Claudio¹; Bauleo, Antonio¹; Catalano, Toni¹; Cotogni, Marco¹; Galvagni, Luigi¹; Pietropaolo, Andrea¹; Taini, Giacomo¹; Venditti, Paolo¹; Huchler, Markus²; Torres, Ramon³; Lokas, Svein³; Bibby, David^3
1Thales Alenia Space Italia, ITALY; ²EADS Astrium GmbH, GERMANY; ³ESA, NETHERLANDS

The GMES Sentinel-1 Earth Radar Observatory, a projects funded by the European Union and developed by ESA, is a constellation of two C-band radar satellites. The satellites have been conceived to be a continuous and reliable source of C-band SAR imagery for operational application such as mapping of global landmasses, coastal zones and monitoring of shipping routes. The Sentinel-1 satellites are being built by an industrial consortium headed by Thales Alenia Space Italy as Prime Contractor.
The main system requirements are presented as drivers for the design of the satellite. The major design challenges as well as the general satellite architecture, the spacecraft subsystems, AIT flow and satellite key performances are outlined. The GMES Sentinel-1 satellite, represents for a LEO spacecraft, the state of the art, in terms of SAR performances, avionics performances, data storage and transmission capability, optical communication link capability, electrical power generation and management and large payload accommodation capability of PRIMA bus.

The key payload is the C-SAR instrument, which has been developed and built under the responsibility of EADS Astrium Germany. The C-SAR Instrument has to provide a dual polarisation capability as well as four operational modes, i.e. Stripmap, Interferometric wideswath, Extra Wideswath as well as Wave Mode. These shall allow for resolutions of up to 5 m x 5 m as well as for swath widths up to 400 km. The demanding operational requirements require an active phased array antenna allowing a fast beam shaping and steering capability in both azimuth an elevation as well as a power full central electronics for command and control of the whole SAR instrument as well as for pulse generation and echo reception, down-conversion, compression and formatting.

The SAR Instrument PFM has just successfully completed its space qualification programme and is now to be integrated on spacecraft level. The presentation will give an overview on the SAR qualification and test programme and on the resulting SAR performance predictions for the in-orbit operations.