Related Research Articles
Sonar is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels. Two types of technology share the name "sonar": passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and SODAR is used for atmospheric investigations. The term sonar is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic) to extremely high (ultrasonic). The study of underwater sound is known as underwater acoustics or hydroacoustics.
Underwater archaeology is archaeology practiced underwater. As with all other branches of archaeology, it evolved from its roots in pre-history and in the classical era to include sites from the historical and industrial eras. Its acceptance has been a relatively late development due to the difficulties of accessing and working underwater sites, and because the application of archaeology to underwater sites initially emerged from the skills and tools developed by shipwreck salvagers. As a result, underwater archaeology initially struggled to establish itself as bona fide archaeological research. The situation changed when universities began teaching the subject and when a theoretical and practical base for the sub-discipline was firmly established. Underwater archaeology now has a number of branches including, after it became broadly accepted in the late 1980s, maritime archaeology: the scientifically based study of past human life, behaviours and cultures and their activities in, on, around and (lately) under the sea, estuaries and rivers. This is most often effected using the physical remains found in, around or under salt or fresh water or buried beneath water-logged sediment. In recent years, the study of submerged WWII sites and of submerged aircraft in the form of underwater aviation archaeology have also emerged as bona fide activity.
Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore oil exploration/offshore oil drilling and related activities. Strong emphasis is placed on soundings, shorelines, tides, currents, seabed and submerged obstructions that relate to the previously mentioned activities. The term hydrography is used synonymously to describe maritime cartography, which in the final stages of the hydrographic process uses the raw data collected through hydrographic survey into information usable by the end user.
A frogman is someone who is trained in scuba diving or swimming underwater in a tactical capacity that includes military, and in some European countries, police work. Such personnel are also known by the more formal names of combat diver, combatant diver, or combat swimmer. The word frogman first arose in the stage name The Fearless Frogman of Paul Boyton in the 1870s and later was claimed by John Spence, an enlisted member of the U.S. Navy and member of the OSS Maritime Unit, to have been applied to him while he was training in a green waterproof suit.
Kongsberg Gruppen is an international technology group that supplies high-technology systems and solutions to customers in the merchant marine, defence, aerospace, offshore oil and gas industries, and renewable and utilities industries.
Thales Underwater Systems (TUS), formerly known as Thomson Marconi Sonar, is an international defence manufacturer specialising in sonar systems for submarines, surface warships, and aircraft as well as communications masts and systems for submarines. TUS is a subsidiary of Thales Naval, part of the Thales Group, and has sites in the United Kingdom, France, and Australia. TUS is made up of three subsidiary companies: TUS Ltd. in the UK, TUS SAS in France and TUS Pty. in Australia, but it operates as a single company with headquarters in southern France. TUS had annual sales of €400 million in 2006 and employed around 2,100 people.
An autonomous underwater vehicle (AUV) is a robot that travels underwater without requiring input from an operator. AUVs constitute part of a larger group of undersea systems known as unmanned underwater vehicles, a classification that includes non-autonomous remotely operated underwater vehicles (ROVs) – controlled and powered from the surface by an operator/pilot via an umbilical or using remote control. In military applications an AUV is more often referred to as an unmanned undersea vehicle (UUV). Underwater gliders are a subclass of AUVs.
Defenses against swimmer incursions are security methods developed to protect watercraft, ports and installations, and other sensitive resources in or near vulnerable waterways from potential threats or intrusions by swimmers or scuba divers.
Underwater Port Security System (UPSS) was developed for the United States Coast Guard and the Maritime Safety and Security Teams (MSSTs) as an anti-frogman technique. It includes the Underwater Inspection System (UIS) and the Integrated Anti-Swimmer System (IAS). Recent developments in terrorism have highlighted the need for underwater anti-frogman security. The UPSS is made in the United States and is reported to be compact enough fit in a large suitcase.
A multibeam echosounder is a type of sonar that is used to map the seabed. Like other sonar systems, multibeam systems emit acoustic waves in a fan shape beneath the transceiver of the multibeam echosounder. The length of time it takes for the sound waves to reflect off the seabed and return to the receiver is used to calculate the water depth. Unlike other sonars, multibeam systems use beamforming to extract directional information from the returning soundwaves, producing a swath of depth readings from a single ping.
Cerberus is an ultrasound Diver Detection Sonar to detect submerged divers. Mod 1 was made by Qinetiq, in their underwater business division. It was unveiled at UDT 2003. The underwater division was sold to ATLAS ELEKTRONIK UK in 2009 and the Mod 2 version was developed by them. It is semi-intelligent and reportedly can detect an air-filled chest cavity underwater and let its operator tell whether the echo is from a man or something irrelevant such as a seal or dolphin, and to distinguish between: a shoal of fish; a ship's wake; a diver with an open-circuit scuba set; a stealth diver with a rebreather; flotsam and jetsam.
Kongsberg Maritime (KM) is a Norwegian technology enterprise within the Kongsberg Gruppen (KOG). Kongsberg Maritime deliver systems for positioning, surveying, navigation, and automation to merchant vessels and offshore installations. Their most well known products exist within dynamic positioning systems, marine automation and surveillance systems, process automation, satellite navigation, and hydroacoustics.
Katanpää-class mine countermeasure vessels are a class of three multipurpose mine countermeasure vessels (MCMV) ordered by the Finnish Navy. The nearly 250 million euro contract was awarded to the Italian shipyard Intermarine S.p.A. in 2006. Initially, all three vessels were scheduled to be delivered by 2014 and the class was expected to achieve operational readiness by 2015, but there have been various delays and the last vessel was handed over to the Finnish Navy in November 2016.
SeaSeep is a combination of 2D seismic data, high resolution multibeam sonar which is an evolutionary advanced form of side-scan sonar, navigated piston coring, heat flow sampling and possibly gravity and magnetic data.
Diver detection sonar (DDS) systems are sonar and acoustic location systems employed underwater for the detection of divers and submerged swimmer delivery vehicles (SDVs). The purpose of this type of sonar system is to provide detection, tracking and classification information on underwater threats that could endanger property and lives. Further, this information is useful only to the extent that it is made available to authorities in time to make possible the desired response to the threat, be it deterrent or defensive action. Subsurface threats are a difficult problem, because reliable detection is available to date chiefly by use of high-resolution active sonar or trained dolphins or sea lions. The threat of an underwater terrorist attack is a concern to the maritime industry and port law enforcement agencies. Ports face a range of threats from swimmers, boat-delivered ordnance such as limpet mines and other forms of improvised underwater explosive devices. DDS systems have been developed to provide underwater security for ports, coastal facilities, offshore installations, pipelines and ships. Due to the variety of life and objects that exist under the water, it is desirable that a DDS system be capable of distinguishing between large sea mammals, shoals of fish; a ship's wake; a diver with an open circuit scuba set and a stealth diver with a rebreather. DDS systems have been developed that can be mounted on the seabed, on a pier or on the hull of a vessel. For complete port security these systems are integrated with the surface surveillance and security systems employed at ports, coastal facilities and offshore installations. Various systems provide specialized features to facilitate their use in port security systems including automatic detection features.
Acoustic seabed classification is the partitioning of a seabed acoustic image into discrete physical entities or classes. This is a particularly active area of development in the field of seabed mapping, marine geophysics, underwater acoustics and benthic habitat mapping. Seabed classification is one route to characterizing the seabed and its habitats. Seabed characterization makes the link between the classified regions and the seabed physical, geological, chemical or biological properties. Acoustic seabed classification is possible using a wide range of acoustic imaging systems including multibeam echosounders, sidescan sonar, single-beam echosounders, interferometric systems and sub-bottom profilers. Seabed classification based on acoustic properties can be divided into two main categories; surficial seabed classification and sub-surface seabed classification. Sub-surface imaging technologies use lower frequency sound to provide higher penetration, whereas surficial imaging technologies provide higher resolution imagery by utilizing higher frequencies.
JASCO Applied Sciences provides scientific consulting services and equipment related to underwater acoustics. It is a group of international companies that provides services and manufactures equipment to predict, measure, assess, and mitigate underwater sound. JASCO provides services on projects worldwide, operating out of 6 locations internationally, to the oil and gas, marine construction, energy, renewable energy, fisheries, maritime transport and defence sectors. The head office is located in Halifax, NS Canada. JASCO employs acousticians, bioacousticians, physicists, marine mammal scientists, engineers, technologists, and project managers.
JFD is a subsidiary of James Fisher & Sons is a Scottish provider of diving equipment and related services.
The RV Denar 2 is a Turkish research and survey vessel owned by TOMA Maritime S.A. Istanbul, Turkey and operated 2E Maritime in Istanbul, Turkey.
References
- ↑ "Canada". Kongsberg Gruppen's corporate website.
- ↑ "Konsberg Gruppen ASA". Archived from the original on 2014-02-28.
- ↑ "Kongsberg Maritime AS". Archived from the original on 2014-02-28.
