f Extensions to Euler's method for three-dimensional potential field interpretation

Reid et al.'s (1990) method for interpreting magnetic survey data in grid form to give source locations and depths uses Euler's homogeneity relation. The relation is formulated in terms of a 'structural index' by which geological constraints are imposed - the index represents the rate of fall-off of the field with distance, which can be calculated for a given source type (thin dyke, finite step, etc.). Reid et al. (1990) used a least squares technique to solve for the source position (lateral coordinates and depth) and regional field value at each grid point, using a window of surrounding values at which the field gradients were known, and the structural index specified. Solutions were accepted or rejected using a criterion which compared the calculated source depth to its standard deviation.