A multibeam sonar system is a form of active sonar that scans the bottom and identifies objects suspended in the water column or affixed to the surface. The sonar’s several physical sensors form a transducer array, which broadcasts and receives sound pulses to map the seafloor or identify other objects. A multibeam array is typically mounted directly to the ship’s hull.
How does it work?
A Van Oord case study tells us that in contrast to single beam sonar, which uses a single transducer to map the bottom, multibeam sonar releases numerous sonar beams (or sound waves) in a fan-shaped pattern simultaneously. This encompasses both the area directly beneath the ship and the space on each side. Multibeam collects two kinds of information: depth to the bottom and backscatter. The time required for the sound to leave the array, strike the bottom, and return to the array determines bathymetry or seabed depth.
Scientists aboard the ship measure the speed of sound in the water they are surveying to convert the two-way transit time between the ship and the bottom to a depth measurement. Backscatter is a measurement of the strength of the sound echo that returns to the multibeam array.
Backscatter data can be used to deduce the geological makeup of the seafloor or individual things on it. Harder, rocky materials, for example, tend to reflect more sound than softer materials like dirt.
Multibeam sonars can also collect backscatter data from objects in the water column that reflect sound. Backscatter data from the water column can be used to display suspended objects in the water column, such as three-dimensional structures associated with shipwrecks, bubble plumes erupting from the bottom, and thick biological layers.
What happens next?
This data is collected onboard by computers, which is then analyzed by hydrographers to generate colorful two- or three-dimensional bathymetric (water depth) maps that aid in seeing the seabed. The warmer colors (red and orange) indicate shallower areas in the bathymetric map below, while the cooler colors (yellow and green) indicate deeper areas.
The Effectiveness of Multi-Beam Sonar
After determining the bottom’s depth, shape, and character, the first step in studying a new place is often to conduct a multibeam sonar marine scan. The sediment character obtained by multibeam offers information on the species that may live nearby, contributing in the process of mapping habitat suitability. The initial multibeam Mapping lays the framework for more in-depth research and investigation of our ocean.
A Multibeam Sonar can be utilized in a wide range of applications.
- Dredging or building beneath the water’s surface
- Producing a bathymetric map
- The turbidity of the water column is being mapped.
- Hydrographic Mapping of the aquatic environment
- Exploration of cultural treasures beneath the sea
Multibeam echo sounders benefit from scanning the sea bed with a fan of narrow acoustic beams, allowing them to cover the bottom completely. The detailed seafloor maps produced are superior to those produced by single-beam Mapping. The maps are developed more quickly, which minimizes the time required for surveys.
Multibeam sonar is the most effective approach for undersea Mapping since it generates the most stunning findings.