Airborne Gravity 2010 - Geoscience Australia

Airborne Gravity 2010
(a)
(b)
Figure 8. 3D density inversion results for the two inversions that utilized the different residual data
sets shown in Figure 7. The models are displayed as isosorfaces enclosing higher density
regions of the subsurface, viewed from southwest.
Discussion
We have examined two aspects of terrain correction in the context of quantitative interpretation of
AGG data for mineral exploration. While efficient algorithms are a requisite tool to perform terrain
correction for large data sets, the details of the correction such as the terrain resolution that is required
and appropriate parameters to simulate the low-pass filtering that was applied to the acquired AGG
data are equally important. We have developed a rapid terrain correction algorithm based on adaptive
quadtree discretization of DEM data that can speed up the calculation significantly. We have also
established a procedure for quantifying the required DEM resolution given knowledge of certain
aspects of the AGG survey such as low-pass filter settings and terrain clearance.
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