A Look Inside Multibeam Sonar Technology

Gideon Anderson

The acronym SONAR refers to a device that utilizes sound to locate things inside a water column (Sound Navigation and Ranging). Active sonars generate their distinct sound waves and analyze the reflected (echo) waves (echosounder). Active sonars include multibeam and single beam sonars. Multibeam sonar can reveal the underwater topography of the soil. R2Sonic offers sonars for marine construction which are built with quality in mind and proven durable. 

What Is the Function of a Multibeam Sonar?

Echosounders operate on the following premise: a projector generates sound waves picked up by a receiver or hydrophone. A transducer is a type of transmitter that can both send and receive sound waves. The travel time or energy of the reflected waves can estimate the depth or kind of seafloor. 


The frequencies transmitted determine the results. Because low frequencies are less absorbed, they can travel further than high frequencies. Low frequencies, as a result, monitor a broader region with lesser resolution than high frequencies.


Multibeam sonar may generate many narrow beams. The transducer, which is placed in the vessel’s keel, emits a variety of sound waves. Consequently, a continuous line perpendicular to the vessel’s movement direction is used to scan the bottom. The swath length is the breadth of each line drawn on the soil. It can be represented in meters or as the angle (in degrees) formed by the line.


The duration and energy differential between produced and reflected sound waves is determined by the transducer. As a result, the depth and characteristics of the seabed may be established since a flat and solid surface reflects more waves than a tilted one.


In addition to scanning the bottom, a vessel equipped with a multibeam sonar may scan the properties of the water column. The emitted beams interact with the particles in the water column, causing reflections to form. The quantity of reflected energy appears to be related to the number of particles in the water column. Particle size and type, as well as transmission frequency. There is now a lot of study being conducted on the link between multibeam data from water columns and turbidity. If you are wondering where to get bathymetric survey equipment figures by simply checking on the collected data that is gathered in your computer. It’s that simple.  

Single Beam vs. Multibeam Sonar

A single beam system with beam widths ranging from 10 to 30 degrees determines depth by measuring the distance between the main beam and the seabed and the shortest slant range. In a sequence of measurements along a given azimuth, multibeam (swath sonar) devices determine slant range and elevation angle. This technique is preferred since it measures the whole seabed rather than just a single line. That is why it is always better to buy multibeam echo sounders because it gives you better coverage of the seabed. 

A Multibeam Sonar can be useful in a variety of circumstances.

  • Underwater construction, often known as dredging
  • Developing a bathymetric map
  • The turbidity of the water column is being mapped.
  • Aquatic habitat mapping
  • Underwater cultural heritage mapping


Multibeam echo sounders benefit from scanning the seafloor with a fan of narrow acoustic beams, allowing them to cover the whole bottom. The resultant seabed maps are more detailed than single-beam mapping. The maps are generated faster, reducing the time required for ship surveys.

Because it delivers the best results, multibeam sonar is the best solution for underwater mapping.