Completed
Summary
The release of a digital elevation model (DEM) for Australia on a 9 arc-second
grid has enabled the computation of gravimetric terrain corrections, therefore
allowing the computation of Bouguer anomalies across the continent.
The terrain correction was calculated through a two-dimensional fast Fourier
transform (FFT) algorithm applied to a linear, planar approximation of the
terrain correction formula, and with a topographic density of 2670 kg/m^3.
The technique was tested on two datasets in order to test for instabilities in
the terrain
correction algorithm: the original 9" DEM, and a 27" DEM
averaged from the 9" data. The 27" terrain corrections were compared with values
supplied by the Australian Geological Survey Organisation (AGSO) in Tasmania:
86% of these data were found to agree within 0.39 mgal; 98%
agreed to within 0.53 mgal (1 sigma).
Results
References
Kirby, J.F. and W.E. Featherstone (1999). Terrain correcting Australian gravity
observations using the national digital elevation model and the fast Fourier
transform, Australian Journal of Earth Sciences, 46:555-562.
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