Technical Papers - Airborne Magnetics

Interpretation of Magnetic Data Using an Enhanced Local Wavenumber (ELW) Method

Ahmed Salem, Airborne Geophysics Department, Nuclear Materials Authority of Egypt,
Dhananjay Ravat, Southern Illinois University at Carbondale,
Richard S. Smith, Fugro Airborne Surveys, 2060 Walkley Road, Ottawa, Ontario, Canada, K1G 3P5; and
Keisuke Ushijima, Kyushu University.

Abstract

This paper presents an enhancement of the local-wavenumber method (named ELW for “enhanced local wavenumber”) for interpretation of profile magnetic data. This method uses the traditional and phase-rotated local wavenumbers to produce a linear equation as a function of the model parameters. The equation can be solved to determine the horizontal location and depth of a 2D magnetic body without specifying a priori information about the nature of the sources.

Using the obtained source-location parameters, the nature of the source can then be inferred. The method was tested using theoretical simulations with random noise over a dike body. It was able to provide both the location and an index characterising the nature of the source body. The practical utility of the method is demonstrated using field examples over dikelike bodies from Canada and Egypt.

Published in Geophysics, March-April, 2005, volume 70, pages L7-L12. © 2005 Society of Exploration Geophysicists. All rights reserved.

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