Edge Enhancement of Magnetic Sources Using the Tilt Angle and Derivatives of Directional Analytic Signals

The analytic signal (AS1) has been widely used for mapping geological features from magnetic data. Some enhanced versions of the AS1 have been introduced to improve its effectiveness. Here, we compare the performance of these filters and introduce a filter obtained from the tilt angle and the directional analytic signals. For better performance on low latitudes, the directional analytic signals are obtained from the vertical integral of the magnetic anomaly rather than its magnetic potential. The proposed filter shows an apparent performance improvement in mapping the edges of magnetic sources, as shown with synthetic models and real example from the Olympic Peninsula, USA. The great advantage of the proposed technique is that the obtained result has lower influence from the magnetization vector direction than the AS1 and other related techniques. The findings demonstrate that the present method not only outlines the boundaries more precisely and clearly, but also reveals the presence of several structures obscured by nonmagnetic sediment in the study area, which are not determined by other methods.