Abstract: Illustrative embodiments of the present invention include methods and apparatus for processing geophysical signals derived from sources located at different positions in a borehole to obtain displacements which are then combined to determine the relative position of formation characteristics. The geophysical signals are correlated by pairs using substantially overlapping correlation intervals to obtain sequences of displacements for each pair. Displacements from each sequence are combined in possible corresponding relationships and classified in an angular classification system relative to the position of the sources of the correlated signals. Displacements from overlapping sequences are also combined and classified, and an analysis is then performed on the classified combinations to determine which combinations are valid.Invalid displacements, for example, are sometimes produced by the failure of the borehole tool used to derive the signals to remain in the preferred position in deviated holes.