The utility of the Magnetic Anomaly Grid Database of Australia (MAGDA) ? computing a massive dataset

Abstract

Public domain total magnetic intensity (TMI) airborne data covering the Australian continent have been collated into a new database of grids. The cell resolution of each grid is optimal with regard to the original survey flight-line spacing. Data for all the grids have been matched in one inverse operation by using the statistics of data differences in the grid boundary overlap regions. Quality control and long wavelength accuracy utilised the independently acquired AWAGS long traverses. A variety of products useful for interpretation, from continental-scale composites to small selected areas of data, can easily be generated from the database. Example processes include reduction to the pole (RTP), upward continuation, horizontal and vertical derivatives, pseudogravity, the analytic signal and multiscale edges. The production of a high-resolution RTP grid of Australia is described, using a super-computer facility, and the calculation of multi-scale edges from the grid.