Estimation of the location and depth parameters of 2D magnetic sources using analytical signals

Abstract

This study presents a different approach to the use of analytic signals of magnetic profile data in the estimation of the polygonal cross-sectional geometry of 2D bodies. The proposed approach uses a technique which aims to estimate the horizontal and vertical coordinates of the corners of a 2D body. To realize this aim, the first step is to estimate the horizontal coordinates of the corners by using the peak amplitudes of the second or higher horizontal derivatives of the analytical signal. The next step is to determine the depths of corners by using a complex formulation of the analytic signal in the frequency domain. In the second step, the complex analytical signal in the frequency domain is solved by an exponential approximation method. Model studies on triangular, trapezoidal and pentagonal cross-sectional bodies yield satisfactory results. To check the performance and applicability conditions, the technique was also applied to magnetic data obtained from the Cataldere magnetite ore deposit in the Bala district of Turkey. The noisy field data prevented us from obtaining more successful results, as in the case of synthetic data applications. © 2008 Nanjing Institute of Geophysical Prospecting.