Depth Determination of Simple Shaped Bodies from Gravity and Magnetic Anomalies by Using Walsh Transforms

Within the scope of this paper, Walsh transform was applied to the total magnetic field and gravity anomalies obtained from the ideal subsurface structures and the field studies and the possibility of this method for the calculation of the depths to the source structures was investigated. This method is based on the Walsh transformation which can be applied to the total magnetic field and gravity anomalies. In this method, initially normalized energy density (NED) spectrum, then the differential energy density (DED) spectrum would be obtained. DED spectrum is the difference between two successive sequency numbers of the NED. The maximum value of sequency numbers (Imax) on DED spectrum is determined and, the depth of the subsurface structure that caused the anomaly can be computed by using of this value in the proper equation. The monopole, line of monopoles, dipole and line of dipoles models were chosen as the ideal subsurface sources for magnetic and sphere, infinite extend horizontal cylinder and semi infinite vertical cylinder for gravity in the theoretical studies and and the anomalies of these structures can be calculated. The depths of the subsurface structures were estimated by using Walsh transform method to the field data and the obtained results were compared with the previously calculated depth with the various other methods. Furthermore, the theoretical and the field magnetic and gravity anomaly data were evaluated with using Fourier-Power Spectrum method.