repeat orbit, one day apart. Since June 1996 ERS-2 has been
the primary operating satellite with ERS-I maintained as
back-up and for occasional tandem campaigns.
ERS-2 is foreseen to operate for at least another couple of
years to provide nearly 10 years of regular active microwave
observations. Moreover, the intention is to allow for inter-
calibration and possible tandem operation of ERS-2 with
ESA's new Earth and atmospheric ENVIronmental SATellite
(ENVISAT) mission currently under development and planned
for launch towards the end of the century.
mission, ERS-1 and ERS-2 were operated in the same 35 day