Scan sides (sometimes also called sonar side scans , sidescan sonar , sonar side imaging , side-imaging sonar and bottom classification sonar ) is a category of sonar systems used to efficiently create large area images of the seabed.
Video Side-scan sonar
Usage
Side-scan sonar can be used to conduct marine archaeological surveys; in conjunction with seabed samples it is able to provide an understanding of material differences and sea floor texture types. Side-scan sonar imagery is also a common tool used to detect objects of debris and other obstructions on the seafloor that may be dangerous for ocean shipping or installation by the oil and gas industry. In addition, the status of pipes and cables on the seabed can be investigated using sonar side-scans. Side-scan data are often obtained along with bathymetric sounds and sub-bottom profiler data, thereby providing a glimpse of shallow seabed structures. Side-scan sonar is also used for fisheries research, dredging operations and environmental studies. It also has military applications including mine detection.
Maps Side-scan sonar
How it works
Side-scans use sonar devices that emit a fan-shaped or pulse shaft toward the seabed across a wide angle perpendicular to the sensor path through water, which may be pulled from a surface or submarine vessel, or mounted on a ship's hull. The intensity of the acoustic reflection of the fan-shaped marine beam is recorded in a series of transverse slices. When sewn together along the direction of movement, these slices form the seabed image inside the plot (width) of the beam. The sound frequencies used in side-scan sonar usually range from 100 to 500 kHz; Higher frequencies yield better resolution but fewer ranges.
History
Technology
The earliest side-scan sonars use single conical-beam transducers. Next, the unit is made with two transducers to cover both sides. The transducer is contained in a package mounted on the hull or with two packets on either side of the ship. Furthermore, the transducer evolves into a fan-shaped block to produce a better sonogram or sonar image. To get closer to the bottom in water, a side scanner transducer is placed in a "tow fish" and pulled by a tow cable.
Until the mid-1980s, commercial side scanning images were produced on paper notes. Early paper records are produced with a sweeping plotter that burns the image into a rolling paper note. Then plotters make it possible to plan position and ship motion information simultaneously onto paper notes. In the late 1980s, commercial systems using newer and cheaper computer systems developed digital scanners that could mimic cheaper analog scanning converters used by military systems to produce images that TV and computer display from scanning, and store them on tape videos. Currently data is stored on computer hard drive or solid-state media.
Military applications
One of the inventors of side-scan sonar is a German scientist, Dr. Julius Hagemann, who was taken to the United States after World War II and worked at the US Naval Defense Mines Laboratory, Panama City, FL from 1947 until his death in 1964. His work is documented in US Patent 4,197,591, first revealed in August 1958, but it was still classified by the US Navy until it was finally released in 1980. The experimental side scan system sonar was made during the 1950s in the laboratory including Scripps Institution of Oceanography and Hudson Laboratories and by Dr. Harold Edgerton at MIT.
The military side-scan sonar was made in 1950 by Westinghouse. The sophisticated system was then developed and built for special military purposes, such as finding a lost H-Bomb at sea or to find a lost Russian submarine, at the Westinghouse facility in Annapolis until the 1990s. This group also produces the first and only work Angle Look Sonar which can track the object while searching under the vehicle.
Commercial applications
The first commercial side-scan system was Kelvin Hughes "Transit Sonar", a sound-echo converted with a single-beam transducer, mounted on a pole, mounted in about 1960. In 1963 Dr. Harold Edgerton, Edward Curley, and John Yules used a 12-kHz side-scan sonic conical-beam to discover the drowning Vineyard Lights in Buzzards Bay, Massachusetts. The team led by Martin Klein in Edgerton, Germeshausen & amp; Grier (later E.G. & G., Inc.) developed the first successful and successful dual-side sonar side-scan system from 1963 to 1966. Martin Klein is generally considered the "father" of a commercial side-scan sonar. In 1967, Edgerton used the Klein sonar to help Alexander McKee find the seeds of Henry VIII Mary Rose . In the same year Klein used sonar to help archaeologist George Bass find a 2000 year old ship off the coast of Turkey. In 1968 Klein founded Klein Associates, Inc. (now L-3/Klein) and continues to work on improvements including the first commercial high-frequency system (500 kHz) and the first dual-frequency side-scan sonar, and the first combined side-sonan and sub-bottom grinding. In 1985, Charles Mazel of Klein Associates produced the first commercially-scaled sonar-side training videos and the first Sonar Side Screening Bookbook and two marine experts discovered the RMS Titanic wreckage.
To survey a large area, GLORIA sidescan sonar was developed by Marconi Underwater Systems and Institute of Oceanographic Sciences (IOS) for NERC. It operated at a relatively low frequency to get remotely. It's used by the US Geological Survey and IOS in the UK to get images from continental shelves around the world.
See also
- Synthesis openings
- Beamforming
- Gradual arrays
- Sonar 2087
- Synthetic aperture sonar
References
External links
- Sonic SonS HDS Marine System
- Sonar Side Scanning
- Use sonar side scan to recover drowned victims
- Images and descriptions of USGS Benthos SIS-1000 sidescan tow sonar vehicles.
- Use of NOAA from sidescan and multibeam sonar to create official US marine chart
- An example of a sidecan geocode image
- Guides for Sonar Scan-side acquisition and image processing and galleries
- Tritech Knowledge Base - Sonars Side Scanning
Source of the article : Wikipedia
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