3D Goussev Filter ? a signal separation and edge detection filter applied to aeromagnetic data in the Great Australian Bight

Abstract

Aeromagnetic data was acquired over a portion of the Ceduna Sub-Basin in the Great Australian Bight for a Non-Exclusive multi client project, prior to the opening of this area for exploration, and several derivative products were generated to enhance the magnetic data prior to interpretation. The shallower sections of the basin were enhanced with the Tilt Derivative, Vertical Derivative and Goussev filters. These routine magnetic grid derivatives were less effective in the deeper parts of the basin. Jacobsen filtering was trialled to create residual products to preserve the signal necessary for further enhancement. A new filter was designed to provide a better enhancement of the magnetic data for signal separation and edge detection in the deeper parts of the Basin. The 3D Goussev Filter is a multi-scale sum or stack of separate applications of the Goussev filter on pseudo-depth slices of the magnetic grid. These pseudo-slices were created by second order Jacobsen filtering with subtraction of successive upward continued residual grids from each other in a stepped methodology. The stacked multi-scale Goussev filter illustrated distinct edge detection from zero contours of the second order residual products and gave an extrapolation into the depth dimension based on the mathematics of the Upward Continuation process. These qualitative products aided in 2D and 3D visualization of the magnetic signal as well as detection of major basement controlling structures. The 3D Goussev Filter separates the super-positioning effects in the potential field data to detect edges and boundaries with pseudo-depth.