Shoreline Detection with Sonars Using Spatial Correlation

Surprisingly accurate traces of shorelines have been obtained with a sonar employing spatial polarity coincidence correlation and interbeam interpolation. Because the shoreline traces have more detail than expected from the basic sonar beamwidth and pulse length, two system aspects should be of interest to acoustic bathymetric survey technology, namely the interbeam interpolation and the dynamic range of the clipped spatial processor and B-Scan display. Finally, when the wideband FM returns were processed through a semicoherent waveform postdetection pulse compression receiver, the shoreline contours were not detectable. This paper presents the sonar traces and related navigation charts, outlines the system used, and suggests reasons for the previously noted behavior.