Estimating the location of magnetic sources using magnetic gradient tensor data

Abstract

In this paper, a new method for the interpretation of magnetic sources is developed using magnetic gradient tensor data. The total magnetisation direction of each magnetic source is estimated, and the magnetic gradient tensor is transformed into tensor data, which would be produced by the same sources with vertical magnetisation. Furthermore, the horizontal edges of the broad steep-sided magnetic sources are estimated from the ratio of the sum of absolute values of the eigenvalues (SAE) and Bzz of the transformed magnetic gradient tensor. The depth estimation of the magnetic sources is obtained using a modified Euler deconvolution method that eliminates the structural index from the equations. The process was tested on both synthetic and measured magnetic data. The results show that this method reduces considerably the effects of total magnetisation and is tolerant to the noise of the data. In addition, this method calculates vertical locations without any prior information about the structural index of the source.