The impact of using jason-1 and cryosat-2 geodetic mission altimetry for gravity field modeling

Since the release of the Danish Technical University DTU10 global marine gravity field in 2010, the amount of geodetic mission altimetry data has nearly tripled. The Cryosat-2 satellite have provided data along its 369 day near repeat since 2010 and as of May 2012 the Jason-1 satellite has been operating in a geodetic mission as part its end of life mission. In this presentation, we perform an investigation of the impact of the Cryosat-2 and Jason-1 geodetic missions on high resolution marine gravity field mapping through comparison with recent high quality marine gravity measured by the United States Naval Ship Bowditch in the Western Pacific Ocean in 2006. Comparisons of pre and post Cryosat- 2/Jason-1 gravity fields illustrated the importance of these new geodetic missions for altimeter marine gravity field mapping. Altimetric gravity derived using 1 year of either Cryosat-2 or Jason-1 is nearly 10% better than gravity derived from retracked and reprocessed combined ERS-1 and Geosat in terms of lower standard deviation with marine gravity. The combination of data fromall four geodetic mission data improves the agreement from around 4.1 mGal to around 3.1 mGal. Accounting for an error estimate of around 1 mGal in the marine gravity observations, it is concluded that for this particularly gravity survey region, the new gravity field from four geodetic missions has an accuracy of about 2 mGal.