The DNSC07 high resolution global marine gravity field

Abstract

1. Summary DNSC07 is a new global ocean wide satellite altimetry derived gravity field computed at the Danish National Space Center (DTUDenmark) with a spatial resolution of 1 arc-minute by 1 arc-minute covering all marine regions of the world including the Arctic Ocean up to the North Pole. For more than a decade satellite altimetry has been used to determine the marine gravity field. All present satellite based global marine gravity fields are based on the GEOSAT and ERS-1 Geodetic Mission (GM) data combined with other satellite derived datasets. The most urgent outstanding problem with most existing marine gravity fields (i.e. KMS02, Sandwell and Smith V12, NTU 01, GSFC00) was to improve the coverage of the data and the quality of the satellite observations in order to gain higher accuracy of the derived marine gravity field in particularly high latitudes and in coastal regions where many sedimentary basins are found. By using a new double-retracking system for the entire ERS-1 GM mission using a highly advanced expert based system of multiple retrackers and subsequently repacking/retracking we have been able to obtain both higher quality data but also many more data than seen before. Especially in coastal and ice-covered regions the new DNSC07 global marine gravity field is superior to other satellite based global marine gravity fields. We will present the high resolution new global marine gravity field and comparison with existing marine gravity surveys in several regions of the world (Indonesia, Florida Keys and East Greenland) and demonstrate how much accuracy have been gained by retracking the satellite observations compared with existing global marine gravity fields.