Sonar/bathymetry
Please contact us more information about our sonar/bathymetry applications
Seabed will provide you suitable solutions in sonar and bathymetry
As a supplier for the hydrographic- and geophysical survey industry, Seabed represents several manufacturers. This enables Seabed to develop various applications that provide turnkey solutions.
Interferometric Sonar
Interferometric sonar systems are used to provide the bathymetry and imagery of the sea-floor by means of an acoustic source. When the outgoing acoustic energy reaches the sea-floor, it is scattered in many directions. Some of the scattered sound energy is reflected back to the transducers mounted on the ship.
These sonar systems accurately measure depths, using both the travel time of the acoustic pulse and the angle of the returning pulse with every linear array. With interferometric sonar systems, the acoustic energy is sent downward from the transducer in the form of a beam. This produces measurements perpendicular to the vessel’s track line. As the vessel moves forward, these profiles sweep out a fan-shaped surface of depth measurements known as a “swath”.
Due to the wide swaths that can be achieved, this technology offers significant advantages in shallow waters. Systems applying this technique can be very useful in the coastal regions for i.e. monitoring of dredging operations, wreck location and pipe line inspection surveys.
Single- and dual beam Echosounders
A single-beam echosounder provides a single depth measurement directly under the transducer. An acoustic pulse with a specific frequency is emitted from the transducer and aimed at the sea-floor. The water depth is then calculated on the basis of the travel time of the emitted pulse. A vessel with a single-beam echo sounder thus produces lines of soundings. A map of contours can be constructed by interpolating the depth values between the survey lines.
Various acoustic frequencies can be used for different applications. The most commonly used frequencies are 200 kHz and 33 kHz. A dual-beam echosounder allows a combination of (these) two frequencies. This can be used to compare the various densities of the sea-floor. The data can be collected using hardcopy (paper), or digitally using survey software for sea-floor mapping.
Multibeam Echosounders
The multi-beam system is based on the compilation of various single-beam transducers mounted in a pre-defined arrangement which enables the system to provide multiple depth measurements.
Like the interferometric sonar system, the acoustic energy is sent from the transducer head downward in a beam and it produces measurements that are perpendicular to the vessel’s survey line. As the vessel moves forward, these profiles sweep out a fan-shaped surface of depth measurements. Because the multi-beam transducer head has a predefined opening angle, (usually 120° or 150°), the Swath widens as the water depth increases.
Multi-beam sonar systems are extremely versatile. They are used for shallow water areas as well as full ocean depths.
To position the soundings correctly, the multi-beam system must be connected to positioning equipment, heading- and motion instruments, as well as a sound velocity sensor. Many of these products are among Seabed’s assortment.
Sub-bottom profiling
The sub-bottom profiler is a geophysical echo-sounding system. The acoustic signal can penetrate the sea-floor due to the low frequencies reached by the echosounder in conjunction with transducers. Depending on the characteristics of the sea-floor, various layers can be made visible in the first few meters.
Side scan sonar
A side scan sonar presents high-quality images. It is used for mapping the seabed and for the detection and identification of underwater objects such as shipwrecks and bathymetric features. The sonar can either be towed from a vessel or mounted on the ship’s hull.
Together with bathymetric sounding and sub-bottom profiler data, side scan data complete the overview of the seafloor and the shallow structure of the sea-floor.
Side scan sonar transducers emit fan-shaped pulses towards the sea-floor, across a wide angle perpendicular to the sensor’s path through the water. The intensity of the acoustic reflections from the sea-floor of this fan-shaped beam is recorded in a series of cross-track slices. The sound frequencies used in side scan sonar usually range from 100 to 500 kHz.
Seabed can provide your organization with high-quality side scan sonar equipment.
We are pleased to support you in finding the right solution for your organisation.
