The quality of some two-dimensional filters in separating regional and local gravity anomalies
B. A. N. C. Apell
Journal name: Geophysical Prospecting
Issue: Vol 22, No 4, December 1974 pp. 601 - 609
Info: Article, PDF ( 481.33Kb )
The separation of regional from local gravity anomalies by means of the application of two-dimensional linear filters is analyzed. It was found that optimization of the filter in the least squares sense leads to filters that produce strong localized concentrations of the error, which may erroneously be interpreted as anomalies. For this reason the maximum absolute value of the error is a more important criterion for the quality of the filter than the root mean square error. This maximum absolute error is minimized by the minimax filter. Intermediate filters are derived which give a transition zone which comes appreciably closer to that of the optimal filter at only a small price in terms of increase of the maximum absolute error.