A Closer Look at Multibeam Sonar Technology

The acronym SONAR refers to a device that utilizes sound to locate things inside a water column (Sound Navigation and Ranging). Active sonar generates its distinct sound waves and analyzes their reflected (echo) waves (echosounder). Active sonars include both multibeam and single beam sonars. The underwater topography of the soil may be seen using multibeam sonar.

Multibeam Sonar Operation

Echosounders operate based on the following principle: a projector generates sound waves picked up by a receiver or hydrophone. A transducer is a device that transmits and receives sound waves. The travel time or energy of reflected waves can be used to estimate the depth or kind of bottom. The frequencies transmitted determine the results. Low frequencies can travel farther than high frequencies due to their lower absorption. As a result, low frequencies cover a wider region with less precision than high frequencies.


Multiple narrow beams can be generated using multibeam sonar. The transducer is installed in the keel of the vessel and produces a variety of sound waves. Consequently, the seabed is scanned parallel to the vessel’s journey direction using a continuous line. The length of the swath is determined by the width of each line drawn on the soil. It can be represented in meters or in terms of the angle (in degrees) formed by the line.

The transducer determines the difference in time and energy between the produced and reflected sound waves. As a result, the depth and characteristics of the seabed can be calculated, as a flat and solid surface reflects more info here on waves than a tilted one does.


In addition to the seabed, a vessel equipped with a multibeam sonar may scan the properties of the water column. The emitted beams interact with the water column’s particles, producing their reflections. On the surface, it seems that the amount of reflected energy is proportionate to the number of particles in the water column. In practice, particle size and type are critical, as is transmission frequency. Numerous studies are now being conducted to determine the link between multibeam data from water columns and turbidity.

Single Beam vs. Multiple Beam Sonar

To know which sonar to use for marine construction, Here is the difference between multibeam and single beam sonars. A single beam system with beam widths ranging from 10 to 30 degrees determines depth by calculating the distance between the main beam and the seabed and the shortest slant range. Multibeam (swath sonar) systems calculate the slant range and elevation angle by a sequence of measurements along a given azimuth. This approach is preferred since it determines the total area of the seabed rather than just one line.

A Multibeam Sonar may be utilized in a variety of circumstances.

  • Dredging or building beneath the water’s surface
  • How to create a bathymetric map
  • Water column turbidity mapping
  • Hydrographic mapping of aquatic environments
  • Cultural heritage mapping under the sea

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In summary

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

Multibeam sonar is the most effective method for underwater mapping since it yields the best results.