Airborne Gravity 2010 - Geoscience Australia

Airborne Gravity 2010
The AGG3D inversion module can import the differential curvature gravity gradients as measured by
the FALCON instrument and perform inversions on selected anomalies or over large areas by tiling.
The user experience involves stepping through a wizard-like series of tabs. These take the user
through the steps of data import from source files in Geosoft format, identification of data and
reference channels, data preparation, 3D mesh set-up, and selection of inversion settings. Figure 2
shows the Data tab from AGG3D where the FALCON data channels and system noise specifications
are set.
Figure 2. Data tab of the AGG3D menu.
The user has options for outputting smooth, i.e., UBC-GIF smooth model style (Li and Oldenburg,
1998) or focusing inversion (Zhdanov et al., 2004) 3D property volumes, and models with scalar
negative, scalar positive, or both scalar positive and negative density contrasts. The inversion itself
may be performed on the user’s local computer, or for larger problems and tiled inversions, sent to a
distributed computing pool which utilises a 64-bit blade cluster.
When an inversion has been completed, profiles of measured versus predicted response can be
displayed, and the 3D volumes of anomalous density are automatically opened and visualised in either
the UBC-GIF MeshTools3d application or in commercial visualisation software. An example of a
density model is shown in Figure 3.
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