On a spectral method for forward gravity field modelling
B. C. Root (TU Delft - Astrodynamics & Space Missions)
P. Novák (University of West Bohemia)
D. Dirkx (Joint Institute for VLBI ERIC, TU Delft - Astrodynamics & Space Missions)
M. Kaban (GFZ Helmholtz-Zentrum für Geoforschung, Russian Academy of Sciences)
W. van der Wal (TU Delft - Astrodynamics & Space Missions)
L. L A Vermeersen (TU Delft - Astrodynamics & Space Missions, TU Delft - Physical and Space Geodesy, NIOZ Royal Netherlands Institute for Sea Research)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
This article reviews a spectral forward gravity field modelling method that was initially designed for topographic/isostatic mass reduction of gravity data. The method transforms 3D spherical density models into gravitational potential fields using a spherical harmonic representation. The binomial series approximation in the approach, which is crucial for its computational efficiency, is examined and an error analysis is performed. It is shown that, this method cannot be used for density layers in crustal and upper mantle regions, because it results in large errors in the modelled potential field. Here, a correction is proposed to mitigate this erroneous behaviour. The improved method is benchmarked with a tesseroid gravity field modelling method and is shown to be accurate within ±4 mGal for a layer representing the Moho density interface, which is below other errors in gravity field studies. After the proposed adjustment the method can be used for the global gravity modelling of the complete Earth's density structure.
help_outline