The downward continuation of the tilt angle

The tilt angle filter T can be used both to enhance images of aeromagnetic data and as the basis of semi-automatic interpretation methods. For vertically magnetised and vertically dipping contacts, resealing T by factor a is equivalent to computing T from sources with all depths decreased by a factor alpha. This downward continuation is much less sensitive to noise than Fourier transform-based downward continuation techniques, and because it reduces interference, it allows more accurate source depth determination from methods such as the tilt-depth method. The method can be applied irrespective of the source and magnetisation type if the tilt angle of the analytic signal amplitude is used.