Open AccessSpace-frequency analysis and reduction of potential field ambiguity
Author(s) -
Maurizio Fedi,
A. Rapolla
Publication year - 1997
Publication title -
annals of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 60
eISSN - 2037-416X
pISSN - 1593-5213
DOI - 10.4401/ag-3858
Subject(s) - wavelet , spectral density , inversion (geology) , ambiguity , continuous wavelet transform , morlet wavelet , mathematical analysis , physics , mathematics , algorithm , geodesy , computational physics , computer science , geology , wavelet transform , seismology , discrete wavelet transform , statistics , artificial intelligence , tectonics , programming language
Ambiguity of depth estimation of magnetic sources via spectral analysis can be reduced representing its field via a set of space-frequency atoms. This is obtained throughout a continuous wavelet transform using a Morlet analyzing wavelet. In the phase-plane representation even a weak contribution related to deep-seated sources is clearly distinguished with respect a more intense effect of a shallow source, also in the presence of a strong noise. Furthermore, a new concept of local power spectrum allows the depth to both the sources to be correctly interpreted. Neither result can be provided by standard Fourier analysis. Another method is proposed to reduce ambiguity by inversion of potential field data lying along the vertical axis. This method allows a depth resolution to gravity or the magnetic methods and below some conditions helps to reduce their inherent ambiguity. Unlike the case of monopoles, inversion of a vertical profile of gravity data above a cubic source gives correct results for the cube side and density