Technical description - Forward Facing Transducer


Bathyswath can optionally be provided with a third, forward-looking transducer. This transducer is rotated both downwards and around its own axis. This provides sonar footprints on the seabed that run diagonally across the track in front of the vessel, which builds up to a third swath of measurements, in the central region between the port and starboard swaths.

Although an interferometer such as Bathyswath provides unparalleled data density, the geometry of the sonar means that this data density is relatively low in the region directly under the transducers. This effect can be mitigated by the third transducer.

< Bathyswath Sonar Head with Forward-Looking Transducer

The results can be seen from Grid Processor data density plots below. These show part of a three-transducer survey, with the third transducer omitted for comparison in the left-hand image. Note that the centre region is well covered, but that there are a few gaps and that the data density in the middle 5 metres is generally less than 5 samples per square metre. In the image on the right, data from the third transducer has been included. The centre region is now covered very well, with data densities greater than 20 samples per square metre, and up to 150 per square metre in places.

The forward-looking transducer is also a valuable safety feature when operating in shallow water, as it gives a warning of submerged obstacles ahead.