Side-scan sonar survey, sales & rent

Side-scan sonar in general:

The side-scan sonar is capable of producing an image of (lost) objects that are lying on the bottom underwater or floating in the water column. Also objects that are almost completely buried in the bottom with only small parts sticking out of the bottom, can be located. To locate or image objects that are completely buried in the bottom without parts sticking out, the side-scan sonar is not appropriate. For this purpose a sub-bottom profiler and/or magnetometer is a suitable device.

How does it work:

Generally under a side-scan sonar system is understood a torpedo shaped body, connected to a computer and/or printer. The body is dragged under or behind a ship, sends out a sonar signal and in return receives the echo's, produced by objects on the bottom or in the water column.

The echo signal caries inside all necessary information to produce an image of an object on a screen or printer and, depending on the type of system, sometimes so clear that it resembles a normal photo. A huge advantage is that side-scan as do all other sonar systems, can produce very sharp images over a relatively large distance in even murky or heavily contaminated water.

The torpedo shaped body or tow fish on the above illustration has been shown in front view. The yellow arcs at the right-hand side illustrate it's transmitted sonar signal which are also present at the left-hand side. This pattern can sometimes cover, depending on several matters, 1000 meters or more. The white lines illustrate the echo of the transmitted signals that where reflected by the illustrated shipwreck and bottom. Also fish and other objects in the water column can generate an echo.

Terminology:

Fish or Towfish: This means the torpedo shaped body that transmits and receives the sonar signal.

Tow cable: This means the cable that drags the torpedo shaped body true the water and carries the transmit/receive data.

Side-scan: Side-scan means sideward looking sonar. The side-scan sonar is mend to  image objects on both sides of the tow fish over a relatively long distance (see illustration)

Echo: This is the signal that is reflected by objects and bounces back to the tow fish.

Depressor wing: This is a wing (acts as a spoiler) that is mounted on top of the tow fish to reach more depth due to an extra generated downward pressure or can be used to stabilize the tow fish in turbulent water.
 

Cable clamp: A cable clamp is intended to get a grip on the tow cable and fasten it at some point on the ship. The clamp is often developed in such a way that it is capable of a quick slack or pulling in the tow cable.

A small summarize of possible side-scan sonar detection and/or inspection applications.

Detection of:

• Shipwreck of wreck parts, debris

• Ship screw

• Airplane wreck or wreck parts

• Car wreck

• Lost cargo

• Lost container

• Drowning victims

Inspection of:

• Pipeline

• Floodgate, Flood threshold, etc.

• Bottom and bottom structure

• Dredging area's

• Flora & Fauna

• Hydraulic constructions

• Bridges, piles, pillars, etc.

In the past years, Metaldec International build up a broad range of experience in the detection and inspection of objects by means of side-scan sonar on a international scale. 

During these survey projects there was also used a KLEIN 595 side-scan sonar with a tow fish (sensor) of 100 kHz and/or 500 kHz or a Imagenex Sportscan  330 kHz and/or 800 kHz, depending on the situation.

Specifications Klein 595:

• Range of the 500 kHz tow fish is max. 150 to 300 meters.

• Range of the 100 kHz tow fish is max. 400 to 1000 meters.

• The standard max. operational depth is 1000 meters.

• Max. horizontal beam angle is 0,2 degrees at 500 kHz and 1 degree at 100 kHz.

The recorder

The recorder does register the sonar images and presents them by means of an internal printer on film paper.

The recorder is connected to the tow fish by means of a coaxial tow cable.

It is possible to choose a setting on the recorder in such a way that it allows the (D)-GPS to generate certain mark lines on the film paper in order to localize objects more easy.

Many different settings are possible and can be chosen according to the need of a particular kind of survey operation. 

Black Laser Learning Side-Scan sonar training on DVD

From september 2005 on, Metaldec became the official European representative of the American company Black Laser Learning (see www.blacklaserlearning.com)

This company develops training DVD's for hydrographic surveyors. These DVD's are meant for the beginner using survey techniques and equipment but also for the more advanced surveyor.

The goal is to develop an assortment DVD's, covering the most equipment that is frequently used in surveys.

In the current assortment already 2 DVD's are available, each handling extremely informative lessons but soon more will follow. Below a list is shown mentioning the traning DVD's that soon will be available and the ones that are available already.

The teaching material is brought mainly using visible illustrations with a minimum amount of text, lost of animations and very clear and understandable. Virtually all issues regarding the subject of the DVD's are discussed.

Click on an illustration or photo to get more information

Available:

• Side-Scan Sonar and Image Interpretation
   

• Side-Scan Sonar and Magnetometers surveys

Soon available:
 

• Subbottom Surveys
   

• Single Beam Hydrographic Surveys
   

• First Responder Search Operations
   

• Advanced Magnetometer Data Processing

(D)-GPS navigation & positioning with Tresco Enginering, Belgium:

Metaldec International, for several years now, is familiar with an affordable yet user friendly, software package named NaviChart (previous called NaviGis)

This software packet makes it possible to carry out a profes-sional survey with the many, on this website mentioned detection equipment, such as sonar, magnetometer, metal detection and more at an affordable prize.

Thales-Navigation offers, true Metaldec International as their dealer, many usable (E)(D)-GPS & LRK equipment. In combination with Tresco NaviChart, there is provided in a very fine piece of software for applications such as side-scan sonar, sub-bottom profiling and many more.

Side-scan sonar images:

Below there are shown several side-scan sonar recordings. Click with the left mouse button on the chosen image to enlarge.

Shipwreck	Barge	Cessna airplane	Shipwreck	Submarine	Tires

Source:        Klein Sonar Systems US