Seabed surveying apparatus for superimposed mapping of topographic and contour-line data

摘要

Disclosed is a seabed surveying apparatus wherein a first acoustic fan beam is transmitted to seabed to provide a two-dimensional topographic representation of echoes from successively greater ranges. A second acoustic fan beam is transmitted to seabed to provide a two-dimensional bathymetric representation of echoes returning from equal profiles of the varying topography. The topographic and bathymetric representations are superimposed on a common X-Y coordinate display field.