The slotted waveguide arrays of the European Remote Sensing Satellites ERS-1 and ERS-2

The European Remote Sensing Satellites, ERS-1 and ERS-2 were launched in 1991 and 1995. ERS-2 is operating and ERS-1 is presently used as backup. The satellites carry an Active Microwave Instrument which comprises a radar scatterometer measuring the wind speed and direction over the oceans and a synthetic aperture radar (SAR) for land mapping. These radars work at C-band, 5.3 GHz. Saab Ericsson Space was responsible for the electrical design and RF tests of the slotted waveguide antenna farm. Slotted waveguide antennas are very well suited for demanding requirements on accurate beamshaping, high gain, very low losses, and sidelobe control. Excellent agreement between theoretically predicted and measured performance has been verified by nearfield tests. The development procedure and our approach to solve certain critical design issues are described in the article.