Comparing the spatial domain and frequency domain algorithms for upward continuation of marine magnetic anomaly

Abstract

Space potential field continuation is a method frequently used for the spatial transformation of magnetic anomaly in the sea area, and is the key technology for constructing three-dimensional marine magnetic field model and the application of marine magnetic survey data. In this study, we analyze the principle of upward continuation of potential field from plane to plane, demonstrate the spatial domain algorithm and frequency domain algorithm, and propose the standards for evaluating the accuracy of the two algorithms. Using the theoretical data of the multi-dipole sphere model, we employ the two algorithms to continue the magnetic anomaly of the observation plane at the height 0 m to 100 m, 200 m, and 300 m, for noisy and noise-free conditions. The results show that the continuation error of the two methods is extremely small at the plane center, but large on the edge; the spatial domain algorithm has obviously better accuracy than the frequency domain algorithm, so it should be preferentially selected in high-precision applications, such as magnetic anomaly detection in the sea area.