Altimetry-Derived Marine Gravity Field Estimation Using Single- and Multi-Satellite Data

• Main Author: G. S. Vergos
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: marine gravity field modeling; sea surface topography; sea; Canada; Newfoundland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.569.4738; http://olimpia.topo.auth.gr/GG2002/SESSION4/vergg2002_gravnewfn.pdf

Abstract. The possibility of improving the determination of the marine gravity field is investigated in an area offshore Newfoundland, Eastern Canada. Multi-satellite (ERS1, GEOSAT) geodetic mission (GM) altimetry data are used in an attempt to improve the estimation of the gravity information inverted from altimetry. Newly estimated altimetry-derived local bathymetry models are implemented in the predictions aiming at providing as smooth residuals as possible before the gravity anomaly prediction takes place. The EGM96 geopotential model is used throughout this study to model the low-frequency part of the gravity field signal, while the altimetry data are corrected for the quasi-stationary sea surface topography (QSST) using the EGM96 dynamic ocean topography (DOT) model. Single- and multi-satellite altimetry-derived gravity anomaly fields are estimated and validated against shipborne gravity data and the KMS01 global altimetric gravity field model. The estimation is carried out in the frequency domain using the efficient 2D planar FFT Stokes convolution and employing discrete spectra for the kernel function. Special attention is paid to the modeling and removal of high-frequency oceanic phenomena contaminating the geodetic mission altimetry data through crossover adjustment and low-pass filtering. From the validation, it is shown that an altimetric gravity field accurate to about 3-5 mGal (1σ) can be estimated, while the combination of multi-satellite data provides greater resolution but does not manage to improve the final accuracy of the solutions.