Comparison of Satellite Altimeter-Derived Gravity Data and Marine Gravity Data

Abstract

Several new satellite altimetry missions have started delivering data that will seriously improve global high resolution gravity fields. The impact of these new geodetic mission data is significant with the quality of the altimetric gravity field nearing that of marine gravity observations in many regions. We demonstrate the quality of the new satellite altimetry data by comparison to high quality marine gravity data over the Capel and Faust basins, offshore Eastern Australia. An improvement of 10% is seen in the region in comparison with vintage altimetric gravity fields. The ready availability of a high-quality marine gravity data over the Capel and Faust basins has allowed us to examine the accuracy of both newly released, as well as vintage, satellite-altimeter-derived gravity data. Statistical analysis of the difference plots show, that over the survey area the newer DTU13 and SSv23p1 gravity data sets have 10% less noise than the vintage DNSC08 data. The spectral analysis shows that for shorter wavelengths (7km–15km) the newer DTU13 and SSv23p1 gravity data have less noise than the historical DNSC08 data. This is primarily due to the recent inclusion of the Jason-1 and Cryosat-2 satellite altimeter data. Over the sampled wavelengths, the DTU13 gravity data appears to have the best resemblance to the reference marine gravity data, exhibiting the overall least difference amplitude over most wavelengths.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015