THE ACCURACY AND APPLICATIONS OF SATELLITE ALTIMETRY

The recently launched TOPEX/POSEIDON altimeter mission is achieving an unprecedented accuracy in the measurement of the absolute sea-level, demonstrating that satellite radar altimetry has evolved into one of t he fundamental instruments for providing synoptic observations of the global oceans with a temporal sampling of a few days to a month. This paper assesses the current estimated accuracy of measurements using th e available satellite radar altimeter systems in observing the absolut e sea-level. The accuracy of sea-level measurements depends on the abi lity to compute accurate orbits of the altimetric satellites, the fide lity of the terrestrial reference system (TRF), and the knowledge of i nstrument biases of the altimeter instruments. In this paper, some app lications of satellite altimetry to contemporary problems in marine ge odesy, oceanography, and global change studies are discussed. Major ad vances for many of these problems are feasible with the abundance of s atellite altimetry missions within this decade. The launch of ERS-1 an d TOPEX/POSEIDON has initiated a decade of high-accuracy measurements of the absolute sea-level from satellite altimetry which holds potenti al for enhancing our knowledge of dynamics of the global ocean, and it s influence on global climate changes.