Depth estimation of gravity and magnetic sources from Wavelet transform spectral analysis

Spectral analysis, based on Fourier Transform, provides a high-resolution analysis in frequency domain but it has not resolution in the space domain. Due to this lack of space resolution, also celebrated methods such as the Spector and Grant’s one, cannot yield information about the position of the source identified in the frequency domain. We propose to fix these issues by resorting to a scalogram analysis, obtained through the continuous wavelet transform of the potential fields, using the Morlet analyzing wavelet. In the scalogram it is indeed possible distinguishing and locating the source contributes for both their space and scale contents. The depths to top and bottom of the potential fields causative sources are investigated locally along bounded subvolumes, subareas, and scale-profiles on the 3D scalogram. The application of such local spectral analysis to synthetic examples and real data leads to results in good agreement  with the known information about the causative sources, providing simultaneously good space and scale resolutions.