On: “Magnetic interpretation using the 3-D analytic signal” (Walter R. Roest, Jacob Verhoef, and Mark Pilkington, GEOPHYSICS, 57, 116–125)

Abstract

Over the last decades increasing interest has been expressed for determining boundaries and depths by using the analytic signal. The basic concepts of the analytic signal in 2-D case for magnetic data were extensively discussed by Nabighian (1972, 1974). Roest et al. (1992) discussed a new method for magnetic interpretation based on the generalization of analytic signal concept to 3-D. They considered that the analytic signal exhibits maxima over magnetization contrasts, independent of the ambient magnetic field, and source magnetization directions and locations of these maxima thus determine the outlines of magnetic sources. Afterward, Hsu et al. (1996) adopted a high‐resolution technique (also related to analytic signal) to image geologic boundaries such as contacts and faults. The outlines of the geologic boundaries can be determined by tracing the maximum amplitudes of an enhanced analytic signal composed of the nth‐order vertical derivative values of two horizontal gradients and one vertical gradient.