Acoustic Seafloor Imaging

Side-Scan Sonar (SSS) offers the prospect of enhanced high-quality imaging of zones that our clients will be interested in. This contrasts with visual inspections and optical observations conducted by divers or ROVs taking photos or video records. Moreover, these are limited in range from several meters to several 10s of meters due to light absorption in water.

OEC can offer acoustic seafloor imaging for areas up to 1,500m deep. The right-hand figure shows waters around Japan up to 200m in depth in yellow and up to 1,500m in depth in pink. In other words, OEC can provide surveys in both of these zones.

Waters greater than 1,500m deep shown in blue in the figure are currently out of range.

There are several types of SSS towfish which provide acoustic seafloor images. OEC operates three types of SSS towfish as follows:

KLEIN SYSTEM-3000, light weight, high resolution traditional SSS operating at a dual frequency of 132kHz and 445kHz.

EdgeTech 4205, a state-of-the-art tri-frequency SSS which can simultaneously apply any pair of frequencies from any of the following: 230kHz, 540kHz and 850kHz.

EdgeTech 2000-DSS, which offers a dual frequency SSS (100kHz and 400kHz) and a SBP (1~12 kHz) for deep waters up to depths of 2000m.

Underwater Positioning System

Underwater tracking of a SSS towfish is conducted by a USBL (Ultra Short Base Line) acoustic positioning system so that accurate coordinates for the image can be logged.

SSS and SBP Simultaneous Recording

During SSS recording, Sub-bottom Profiling records can also be obtained at the same time when employing the EdgeTech 2000-DSS. This SSS towfish can be towed by either a lightweight cable or an armored cable reeled on a drum winch. OEC has two winches: one of them is capable of reeling 500m of armored coaxed cable and the other has a 3000m cable capacity.