PASCO provides clear acoustic digital images of the seabed through the latest digital side scan sonar (Sound, Navigation and Ranging) technique. We propose application and utilization of this seabed exploration technology in the form of studies of sedimentation distribution and effluent, among others.
What is a Side Scan Sonar?
Side scan sonar transmits acoustic waves from a device known as a "fish." The acoustic waves spread out in a fan-shape toward the seabed and disperse on the seabed. The sonar then receives the sound waves that are reflected from the seabed, thereby capturing the surface of the seabed in the form of an image. The strength of the sound waves that are bounced back from the seabed reflects sedimentation and objects on the seabed. As such, by displaying the strength or weakness of these acoustic waves through dense or light shades, it is possible to view the seabed in the form of an image resembling a photograph.
The seabed image that is acquired typically comprise white-colored records that represent hard objects such as rocks or structures, and records in dense shades that represent soft objects such as sand or mud. It is thus possible to categorize the sedimentation categories for the target waters.
In addition, as records from side scan sonar are able to capture the shapes of objects on the seabed, the technology can also be utilized to locate spillage and effluent, such as shipwrecks.
Side Scan Sonar SYSTEM3000
The side scan sonar SYSTEM3000 owned by PASCO is a state-of-the-art machine manufactured by L-3 Klein, a U.S. company. Through a newly developed transducer and circuit, it has succeeded in producing clear image data of seabed records where they used to be murky and unclear. This machine was developed to enable it to cover a broad range of 100 to 150 m broadside. For this reason, not only is it able to capture seabed conditions and fallen objects in an efficient manner, it is also able to capture differences in seabed sedimentation as well as the spread and overgrowth situation of seaweed beds. In addition, through a data-recording device, it is able to carry out surveying activities while simultaneously displaying the data on multiple computers. The data recorded is output as GeoTIFF mosaic images of the seabed, and thus can be utilized in the same format as GIS data.
Combination with Narrow Multibeam Sounding System
By synthesizing the sedimentation distribution data obtained from the side scan sonar, with detailed seabed topographical data obtained from the state-of-the-art narrow multibeam sounding equipment owned by PASCO, it is possible to draw up a 3D sedimentation distribution map and get a grasp of the topography and sedimentation conditions at a glance.
As this can also be applied to the computation of the volume of obstructive objects that have sunk onto the seabed, depending on the objectives of the survey, it may also be effective to combine this with a survey conducted using a narrow multibeam sounding device.
Getting an Accurate Interpretation of the Rubble and Shipwrecks in the Water
The side scan sonar SYSTEM3000 boasts a high degree of precision and resolution. Taking advantage of these characteristics, the sonar can also prove useful in hunting obstructive objects in the water, such as rubble and shipwrecks. As it can also capture the shapes of these objects clearly, it is easy to gain an idea of what the target object is and get an accurate interpretation of the position coordinates of the object. In this sense, the sonar can be utilized to obtain basic information for removal work.