The Radar Altimeter is a Ku-band (13.8 GHz) nadir-pointing active microwave sensor designed to measure the time return echoes from ocean and ice surfaces.
The Along Track Scanning Radiometer consists of an Infra-Red Radiometer (IRR) and a Microwave Sounder (MWS). On board ERS-1 the IRR is a four-channel infra-red radiometer used for measuring sea-surface temperatures (SST) and cloud-top temperatures, whereas on board ERS-2 the IRR is equipped with additional visible channels for vegetation monitoring.
Global Ozone Monitoring Experiment, a nadir-scanning ultraviolet and visible spectrometer for global monitoring of atmospheric Ozone, was launched on-board ERS-2 in April 1995. Since summer 1996, ESA has been delivering to users three-day GOME global observations of total ozone, nitrogen dioxide and related cloud information.
The main objective of the microwave radiometer (MWR) is the measurement of the integrated atmospheric water vapour column and cloud liquid water content, as correction terms for the radar altimeter signal.
Synthetic Aperture Radar wave mode provides two-dimensional spectra of ocean surface waves. In image mode the SAR provides high resolution two-dimensional images with a spatial resolution of 26 m in range (across track) and between 6 and 30 m in azimuth (along track). Image data is acquired for a maximum duration of approximately ten minutes per orbit.
The purpose of the Wind Scatterometer is to obtain information on wind speed and direction at the sea surface for incorporation into models, global statistics and climatological datasets. It operates by recording the change in radar reflectivity of the sea due to the perturbation of small ripples by the wind close to the surface.
The Precise Range And Range-Rate Equipment PRARE is a compact, space-borne, two-way, two-frequency microwave satellite tracking system.