(ERS) a satellite incorporating a C-band radar system operated by the European Space Agency and consisting of C band (6 cm) synthetic aperture radar (SAR) and wind scatterometer sensors —note 1. ERS SAR imagery is designed for monitoring polar sea ice and has been used for terrestrial and oceanic surveys —note 2. the ERS wind scatterometer is used for monitoring ocean surface wind and waves This definition last updated 10/25/2008