Gravity, Geoid and Marine Geodesy pp 400-407 | Cite as
A Comparison of Marine Gravity Field Modeling Methods Using Non-Isotropic A-Priori Information
Abstract
The computation of quantities related to the gravity field, e.g., gravity anomalies and geoid heights, using Least Squares Collocation (LSC) requires isotropic covariance functions in order to simplify the computation and the derivation of the self-consistent covariance functions. The assumption of the isotropic structure of the gravity field restricts the accuracies of the predicted quantities obtained by LSC. The spectral methods based on the Input-Output System Theory (IOST) can use both isotropic and non-isotropic Power Spectral Density functions (PSDs) easily. In this study, a comparison of the accuracies of the predicted gravity anomalies and geoid heights is carried out using (a) non-isotropic a-priori information and (b) isotropic a-priori information. The recovery of the gravity field is made by combining sea gravity data and satellite altimeter data from the Geodetic Mission (GM) of ERS-1. The results show that higher prediction accuracies are always obtained when using non-isotropic information instead of the isotropic one. The non-isotropic a-priori information is derived directly from the data without any adjustment or model fitting procedure.
Keywords
Gravity Field Gravity Anomaly Test Area Gravity Data Satellite AltimetryPreview
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