Structural mapping of potential field sources using BHG filter

Abstract

Edge detection is one of the most commonly used interpretation techniques applied to potential data for detecting subsurface susceptibility/density discontinuities. Several edge detection techniques utilize the first, second, or even third-order gradients of the magnetic field to delineate the susceptibility contrasting zones. A new filter called Balanced Horizontal Gradient (BHG) filter is designed for enhancing the edges of the subsurface bodies that overcomes the limitations of the conventional filters. The BHG filter is based on the arctangent function of derivatives of horizontal gradients. The main advantage of the proposed filter is that it seems to detect all the source edges with no false edges generated around the true edges and effectively balances the edges arising from the shallow and deep-seated sources. We applied the filter on the aeromagnetic data from central India and identified the extensions of the Godavari rift and central Indian shear underneath the Deccan volcanic province.