HR: 1330h
AN: GP13A-01    [Abstracts]
TI: Model-based Separation Filtering of Magnetic Data
AU: * Pilkington, M
EM: mpilking@nrcan.gc.ca
AF: Geological Survey of Canada, 615 Booth Street, Ottawa, ON K1A 0E9 Canada
AU: Cowan, D R
AF: Cowan Geodata Services, 12 Edna Road, Dalkeith, WA 6009 Australia
AB: Separating the fields produced by sources at different depths is a common requirement in the interpretation of potential field data. Approaches to this problem are generally data- or model-based. Data-based methods rely on breaks in the slope of the logarithmic power spectrum of the observed field to design filters that can effect the separation. When the power spectrum shows no identifiable spectral slope breaks, other approaches are necessary. We outline a model-based method that does not depend on power spectral information but requires estimates of the average depths of the source distributions. An ensemble of models is computed based on these known values and a set of filter parameters are determined that produce the closest fit (in a least-squares sense) to the theoretical fields generated by each source distribution. This approach is used to separate basement effects from intrasedimentary sources in magnetic data collected over the Colville Hills, Northwest Territories, Canada.
DE: 0903 Computational methods, potential fields
DE: 0925 Magnetic and electrical methods
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2005 Joint Assembly