Depth estimation from downward continuation: an entropy-based approach

Summary We propose a new approach to the study the Normalized Full Gradient, based on assessing the entropy of the normalized downward continued field at each level of continuation. We show that the estimated entropy may be efficiently used to obtain information about potential fields source depth. As entropy decreases when the information is concentrated, we should detect the source depth at the continuation level where the entropy has a local minimum. We test this idea on synthetic and real magnetic data and found rather accurate results.