One-step compensation downward continuation method free of iteration in wave number domain

Abstract

As a kind of geomagnetic data processing, downward continuation of potential field plays an important role in geologic interpretation and geomagnetic localization. The inherent instability of larger distance downward continuation restricts its practical applications. In this paper, we report a kind of one-step compensation downward continuation method free of iteration using the equivalent wave number domain continuation operator, which will speed downward continuation compared to iterative compensation, and prove theoretically the convergence of the downward continuation filtering factor about one-step immune-iterative compensation. The frequency responses of the low-pass filter factor are also discussed by different damping factors, iterative numbers and continuation depths. The regularity analysis of one-step compensation method is also discussed. We use the theoretical model of magnetic bodies and real data to test experimentally the immune-iterative compensation algorithm based on the equivalent wave number domain continuation factor, respectively. The results all show high accuracy and good stability of the one-step compensation downward continuation algorithm. The performances of downward continuation including three kinds of algorithms are demonstrated by three parameters, and comparisons prove the reported algorithm has less calculated error than the generalized inverse method, and less elapsed time than the iterative compensation method.