From satellite altimetry to ocean topography A survey of data processing techniques

Satellite altimetry was introduced as a brief experiment on Skylab in 1973. Since this experiment, operational radar altimeters have been flown on GEOS-3 and Seasat and currently the Geosat altimetry misssion is in progress. For the early 1990s additional altimeters are planned for launch on the European ERS-1 and ERS-2 satellites, the U.S.-French Topex/Poseidon satellite, the U.S.NROSS satellite and the Japanese MOS-2 satellite. This paper presents a brief survey of altimetry missions and of some important aspects of altimeter data processing. In addition, the topic of orbit computation accuracy is addressed in somewhat more detail and some examples of geophysical products obtained from Seasat altimeter measurements are discussed. These examples do not necessarily represent products of the highestachievablequality, but they serve to illustrate the possibilities and limitations of present-day processing techniques.