ALONG-TRACK DYNAMICAL TOPOGRAPHY BY GEOSAT, ERS-1 AND TOPEX POSEIDON ALTIMETERS WITH A NEW GEOID MODEL/

A new gravitational equipotential (geoid) model estimates that has bee n developed up to spherical harmonic expansion to 360 degree have been described. These model coefficients help in defining improved represe ntations of the earth's gravitational potential beyond that available from just satellite or terrestrial data and are the current state of a rt potential coefficients. The old and new geoid model estimates are c ompared and assessed with the along track sea surface height measureme nt by Geosat, ERS-1 and Topex/Poseidon (T/P) altimeters. Dynamic topog raphy with reference to old and new geoid are also estimated and analy sed. Assessment of all the altimeters is aimed for futuristic goal of estimating the climatic dynamic topographic signal over the Indian Oce an with a single standard geoid reference datum.