Textural filtering of aeromagnetic data

Abstract

The qualitative interpretation of aeromagnetic data relies on amplitude and textural variations within the data to map different geological units. An interpretation is commonly based on a suite of images where the data have been subjected to various filtering operations designed to highlight different characteristics. Most of these filtering operations respond primarily to amplitude variations within the data. An alternative approach is to use filters that respond to variations in the texture, that is spatial variation of amplitude. There are a number of different methods of filtering in this manner including simple statistical transforms, methods based on grey-level co-occurrence matrices, methods using fractal measures and a method based on the textural spectrum. These methods have mainly been developed for use in the medical and cartographic fields. Preliminary trials suggest such filters can extract additional structural and stratigraphic information from aeromagnetic data which complements that derived from the standard amplitude-based filtering operations.