The Envisat Radar Altimeter system (RA-2)

Following on from the great success of its ERS-1 and -2 satellites, which h ave contributed to a much better understanding of the role that oceans and ice play in determining global climate, ESA is currently preparing Envisat, Europe's largest remote-sensing satellite to date, for launch. Its payload includes an advanced instrument complement designed to guarantee the conti nuity of observations started by its predecessors and to meet the global Ea rth-monitoring requirement on a longer time scale. In particular, the altim etry from Envisat will benefit from the improved performance of a dual-freq uency Radar Altimeter (RA-2) working in synergy with the Microwave Radiomet er (MWR) and Doppler Orbitography and Radio-positioning Integrated by Satel lite (DORIS) instruments. The ground processing products that will be avail able in near-real-time will be as comprehensive as the off-line products, d iffering only in terms of the availability and quality of the auxiliary dat a.