A novel approach based on the fast sigmoid function for interpretation of potential field data

Edge detection of geological structures is an important objective in interpretation of potential field data. Although many methods have been proposed to highlight the edges of the subsurface structures, it is still the focus of many researchers to derive new techniques or enhance existing methods that can improve resolution within this scope. Here, we introduce an enhanced edge detection filter (FSED) based on a modified fast sigmoid function and the vertical and horizontal derivatives of the total horizontal gradient of the potential field data. The efficiency of the proposed filter was tested on synthetic data and the results were also compared with those obtained from other commonly used filters. The test results showed that the proposed filter could not only balance anomalies from shallow and deep sources, but also more accurately determine the edge location of these structures. The application of the proposed filter using real data was carried out on the gravity and magnetic data from Vietnam. For both the data, the FSED provided more detailed and clearer horizontal location of edges of causative structures. This filter is therefore promising to be a better tool for qualitative interpretation of potential field data compared to other popular filters.