HIGH-RESOLUTION SEA-BED IMAGING - AN ACOUSTIC MULTIPLE TRANSDUCER ARRAY

A high-resolution sea-bed profiling system is described. The multiple transducer array (MTA) consists of a 37 element linear array of ultra- sonic (5 MHz) transducers. The first prototype MTA described herein me asures two-dimensional bedform profiles over a length of 45 cm with ap proximately 1 mm vertical resolution and 2 cm horizontal resolution. C omplete profiles can be recorded every five seconds. Laboratory and fi eld tests of the MTA show the system's capability to accurately measur e bedforms of known geometry and the ability to work under conditions with relatively high suspended sediment concentrations. Previous high- resolution profiling systems have either had moving parts, or have bee n unable to obtain the resolution of the system described here.