(wur’ n∂r) A method of inverting regularly spaced magnetic data such as obtained from aeromagnetic surveys. The method assumes that anomalies are produced by thin sheets or planar interfaces with infinite strike and depth extent which are perpendicular to the line of measurement. The anomaly produced by a thin sheet can be expressed in terms of four unknowns so that, in a noise-free environment, values at four successive points suffice for a solution. Similarly, the vertical or horizontal derivative of the anomaly produced by a planar interface between rocks of differing magnetization can be expressed in terms of four unknowns. Usually two (sometimes three) additional unknowns are added to allow for interferences and a solution is found for each successive 6 (or 7) points on an overlapping basis. The results (which consist of position, depth, dip, and susceptibility contrast or thickness) are subsequently analyzed to remove erratic solutions. The relation between an anomaly and its magnetic source is expressed as a convolution, hence calling the operation deconvolution (or sometimes filtering). See Hartman et al. (1971, 891–918).