Technical Description - Specifications



Bathyswath is a low cost, high performance bathymetry and sidescan system suitable for installation on dedicated vessels, ships of opportunity, and remote platforms, including UUVs and USVs. It is simple to integrate into a full survey suite.

It is intended for mapping the bottom of the sea and inland waterways. The transducers are mounted on pole, hull or underwater platform, and can be used to survey up to about 300 metres water depth (or altitude, for an underwater platform). The end products of the system are images and charts of the depth and strength of reflection of the seabed. These products are known as bathymetry and sidescan respectively.

Bathyswath is available in three frequency versions, 117, 234 and 468 kHz for up to respectively 300, 150 and 75 m slant range. The system accuracy of all versions exceeds the latest IHO specifications, as set out in IHO Standards for Hydrographic Surveys, Special Publication 44, 5th Edition, February 2008.

Operating in Microsoft Windows, and with full on line help and manual, the system is easy to operate and extremely robust.

Data acquisition mode stores all raw data output from the transducers while the real time displays allow processing and/or QA. A coverage plot assists in survey line planning.

Data processing abilities include swath generation with speed of sound profile correction, swath gridding and fairsheet plots. Final data sets consist of correct positional x,y,z & a (amplitude) data. These xyza DTMs can be interrogated, viewed, exchanged and printed by the Bathyswath software and third party charting and DTM display software. Processing may be carried out on the survey workstation or another PC running Windows.


Bathyswath requires clean electrical power either of 110-240 Volts, at around 200W (for desktop and industrial computer systems), or 12-25V DC, at around 25W.

When using mains power, the use of an Uninterruptible Power Supply (UPS) or Line Volt Conditioner (LVC) is recommended, in order to ensure a clean and continuous supply. In situations where the survey vessel is unable to supply the required power, a generator should be used. The use of a small generator may also require the use of an UPS or LVC. Alternatively, the output from a choice of generators may be sampled using an oscilloscope or by connecting the Bathyswath system and inspecting the level of noise in the Amplitude window of the Swath program. Inverters can also be used to provide mains power from batteries, but these frequently give a very noisy output.



Bathyswath is used with external computers and sensors, such as the following. These can be supplied with the Bathyswath system, or users may obtain their own.


The Transducer Interface Unit (TIU) includes the Transducer Electronic Modules (TEM), a USB hub and a Power Supply Unit (PSU). There is one TEM per transducer.

At present, the TIU is either inside a splash enclosure (IP65, 210 x 74 x 461 mm, 5 kg) or a dry one (294 x 125 x 285 mm, 6.4 kg).


In the diagrams below, dimensions are in millimetres unless otherwise stated.


Bathyswath systems are supplied with a “V”-bracket. The dimensions of the bracket assemblies, fitted with transducers, are as follows:


Bathyswath-XL Technical Parameters

Mass and Weight Budget for a Typical Bathyswath-XL Installation