A tool for analysing depth resolution in potential-field inversion

A careful management of the ambiguities and errors in potential field inversion is crucial for obtaining reliable information about the source distribution with respect to depth. In this paper we introduce a tool, the ApproxDRP, which is based on an approximation of the singular vectors obtained by the iterative Lanczos bidiagonalization algorithm. This tool allows a computational/visual analysis of how much the depth resolution in a potential-field inversion problem is influenced by the way the problem is discretized and regularized. Since the ApproxDRP is based on an iterative method, it is suitable for large-scale problems. We show that when used in combination with a plot of the approximate SVD quantities, the ApproxDRP may successfully show the limitations of depth resolution resulting from noise in the data. This allows a reliable analysis of the retrievable depth information and effectively guides the user in choosing the optimal number of iterations, for a given problem.