IMPROVED RESOLUTION OF GEOSAT ALTIMETRY USING DENSE SAMPLING AND POLYNOMIAL ADJUSTED AVERAGING

The altimeter data processing technique presented here improves the sp atial wavelength resolution of Geosat ERM by smoothing the 10 Hz data, using measurements of the wave height and averaging repeated (colline ar) altimeter measurements. For each repeated track, the residuals bet ween its height profile and the mean height profile were modelled with a third degree polynomial and then subtracted from the data and input in a new averaging. The 10 Hz sampling rate is shown to contain a gre ater portion of short-wavelength signal than the standard 1 Hz data fo rmat. The effective precision is determined to be 1.5 cm, and the alon g-track wavelength resolution limit is determined to be 19 km.