COMPENSATION OF SONAR IMAGE DATA PRIMARILY FOR SEABED CLASSIFICATION

摘要

The composition of the seabed can be assessed by measuring the amplitude of sound backscattered from the seabed. However, the recorded amplitude varies not only with the type of material present on the seabed but also with the range travelled to and the angle of incidence of the transmitted pulse at the seabed. This invention is a method for adjusting the amplitudes of backscattered echoes to reduce the distorting effects on sonar amplitude image data of both range and angle of incidence. A compensation table is created, each cell of which is associated with a unique combination of range and angle-of-incidence data values. Each cell contains amplitude image summary data associated with correlated range and angle-of-incidence data for such cell. The associated range and angle-of-incidence data lie within respective selected partitions of range and angle-of-incidence data determined by selected statistically significant compilations of range and angle-of-incidence data. The amplitude image data values are then compensated in dependence upon the compensation table in generating fresh amplitude image data values for further processing.