Effect of signal amplitude on magnetic depth estimations

The magnetic signal generated over any source can be analyzed in terms of the two basic components of any wave: frequency (λ) and amplitude (A). With respect to magnetics, the frequency will be a function of the magnetic source body depth and geometry, while the amplitude is a function of magnetization intensity (magnetic susceptibility and natural remanent magnetization, NRM, if present). Many processing and interpretation methods developed over the last 50 years take advantage of the intrinsic relationship between frequency and depth to generate a variety of depth-estimation routines. Furthermore, many methods are independent of magnetic susceptibility (and therefore amplitude) contrasts since the methods incorporate some sort of mathematical expression that nulls the effect of varying susceptibilities.