Using Multibeam Sonar to Collect Hydrographic Data
Most multibeam systems are hard mounted to either the bottom of a vessel’s hull or on a pole or arm that is on one side of a vessel. Click image for larger view and complete caption.
Multibeam echo sounder systems (MBES) represent the current generation of echo sounding technology that was originally developed by the U.S. Navy some 30 years ago.
MBES are primarily used today to acquire full- and partial- bottom bathymetric coverage, to determine least depths over critical items such as rocks, wrecks, obstructions, and other navigation hazards. These systems emit sound waves and then measure and record the time elapsed between the emission of the signal from the transducers to the seafloor or object and back again. MBES also have the ability to produce a "swath" of soundings (i.e., depths) to ensure full bottom coverage of a particular area.
The shipwreck Herbert D. Maxwell depicted by Digital Terrain Model generated from multibeam sonar data. Click image for larger view and complete caption.
Multibeam systems can have more than 100 transducers, which can compute accurate depths that cover a distance on either side of the ship equal to about four times the water depth. MBES obtain large amounts of data that can produce high-resolution models of the seafloor.