ESSAI DE FILTRAGE NON-LINEAIRE APPLIQUE AUX PROFILS AEROMAGNETIQUES*

Digital aeromagnetic profiles recorded with a high accuracy can be filtered with an electronic computer. Linear filtering is not very efficient, because the frequency spectrum of a given anomaly is very wide. But other methods are possible which, through a step by step analysis of the profile, leave some categories of anomalies unaltered while they remove the others completely. Our method uses as a criterium the width of the anomalies; it distinguishes and processes differently “bell-shaped” and “multi-legged” anomalies. Some examples of the use of the method are shown.     

UNE METHODE D'ANALYSE FINE DES PROFILS AEROMAGNETIQUES *

A method to analyse aeromagnetic profiles is proposed: several horizontal (width-) and vertical (amplitude-) parameters are deduced from the anomalies. These parameters are then compared with diagrams drawn on a logarithmic scale. The comparison yields depth and magnetization of the causative bodies. The method lends itself equally well to a quick estimate and to a thorough interpretation, depending on the number of parameters deduced and on the number of diagrams. It can be applied also to the anomalies of the total field and its vertical gradient.