Technical Description - System Description, functionality & Versions

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SYSTEM DESCRIPTION

The main components of a Bathyswath system are sonar transducers and Transducer Interface Unit. Each system is supplied complete with software, with real-time functions for data acquisition, processing functions for the acquired data and QA functions for survey accuracy. The system can easily be integrated into a survey suite to allow the acquisition of all relevant position, orientation and environmental data to enable accurate survey output.

The Bathyswath architecture is very flexible. It can be configured to work on small boats and large ships, AUVs, ASVs and ROVs. The system can be operated over long cables and in computer networks. A range of sonar frequencies is available to suit the application: from deep water to high-resolution shallow water surveys.

 

SYSTEM FUNCTIONALITY

A swath system is one that sends out sonar signals either side of the ship, in a beam that is wide in the vertical direction but narrow in the horizontal direction. These beams form a “footprint” on the seabed that is a narrow strip at right angles to the direction of travel. As the ship moves forwards, a ribbon-shaped swath of seabed measurements is built up.

Bathyswath simultaneously measures two kinds of information: the direction of the echoes from the seabed, and the strength of the signal.

The first is used to measure the depth of the seabed (bathymetry), and the second is used to provide a black-and-white image (sidescan).

For operation from the surface, the transducer(s) may be fixed to the hull of a survey vessel, or to a pole or other portable fixture. By measuring and recording the motion and location of the transducers, the depth information is correctly located with respect to a survey grid system. Displays shown in real time allow the seabed to be inspected while the survey is underway.The post-processing software supplied with the system allows the data recorded during a survey to be processed into a continuous surface for charting in the form of a Digital Terrain Model (DTM).

Additional processing can provide bottom contour charts, Individual depth soundings and oblique 3-Dimensional views of the data set. In addition, the attributes of sonar reflectivity may be 'draped' onto these views or used to compute the bottom material encountered. Several third-party post-processing software packages now have interfaces for Bathyswath data sets (QINSy, SonarWiz, Hypack, etc.).

 

VERSIONS & OPTIONS

The standard Bathyswath system is available in three sonar frequencies: 117, 234 and 468 kHz. The higher frequencies have smaller, lighter transducers and higher resolution, but smaller range and depth capability.

A third, forward-looking, transducer can be supplied. This helps to increase the data density in the region directly below the transducers. Click for Page.

Several electronic housing types are available, including a splash-proof one for use on deck or in open boats but limited to 2-transducer systems, and a desktop unit which can be used in a rack or as a stand-alone unit.

The system can be supplied complete, ready to use, or in OEM form, as a kit of parts, to be incorporated into vehicles or vessels. Click for Page.

Modular “bottles” can be provided for small AUVs, including Gavia (Teledyne Gavia) and REMUS 100 (Kongsberg). Click for Page.

A 40 kHz, 6000-metre pressure-rated, version is available, for full-ocean-depth survey work. Click for Page.