Using parity decomposition for interpreting magnetic anomalies from dikes having arbitrary dip angles, induced and remanent magnetization

Abstract

We have developed a technique to reconstruct the magnetic anomaly due to a dike in a way that the effect of magnetization direction is removed, resulting in a new totally symmetric anomaly. The reconstruction algorithm is easy to implement and could avoid the need of reduction to the pole at a low computational cost. The method is based on the decomposition of the function representing magnetic anomalies due to dikes in its even and odd parts. After applying a Hilbert transform to the odd components, we reconstruct the signal by a weighted average of the even part and the Hilbert-transformed odd part of the signal. The method requires knowing the dike’s center position, which is accomplished by locating the center of symmetry of the analytic signal amplitude as well as the effective dip angle obtained by evaluating the anomaly’s tilt angle. Our approach is tested for synthetic and field data. As an illustration of the method’s potential applications, we use it to estimate the width and depth of magnetic dikes.