Sonar is a technique that uses sound propagation to navigate, measure distances (ranging), 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.
Side-scan sonar is a category of sonar system that is used to efficiently create an image of large areas of the sea floor.
Echo sounding or depth sounding is the use of sonar for ranging, normally to determine the depth of water (bathymetry). It involves transmitting acoustic waves into water and recording the time interval between emission and return of a pulse; the resulting time of flight, along with knowledge of the speed of sound in water, allows determining the distance between sonar and target. This information is then typically used for navigation purposes or in order to obtain depths for charting purposes.
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.
The Echo class is a class of multi-purpose hydrographic survey ships in commission with the Royal Navy. The ships are primarily tasked with conducting survey work in support of submarine and amphibious operations, however, the class also has a secondary role in mine countermeasures. The two vessels of the class are the most recent additions to the Royal Navy's Hydrographic Squadron. Each ship displaces approximately 3,700 tonnes, and is equipped with a state of the art suite of equipment.
HMS Echo is the first of two multi-role hydrographic survey ships commissioned by the Royal Navy. With her sister ship, HMS Enterprise, they form the Echo class of survey vessels. She was built by Appledore Shipbuilders in Devon in 2002 and is the ninth Royal Navy vessel to carry the name.
HMS Enterprise, the tenth ship to bear this name, is a multi-role survey vessel - hydrographic oceanographic (SVHO) of the Royal Navy. She has a sister ship, HMS Echo, and together they make up the Echo class of survey vessels.
The Italian Navy is the navy of the Italian Republic. It is one of the four branches of Italian Armed Forces and was formed in 1946 from what remained of the Regia Marina after World War II. As of August 2014, the Italian Navy had a strength of 30,923 active personnel, with approximately 184 vessels in service, including minor auxiliary vessels. It is considered a multiregional and a blue-water navy.
HMAS Leeuwin is the lead ship of the Leeuwin-class of hydrographic survey vessels operated by the Royal Australian Navy (RAN).
The Leeuwin class is a two-ship class of hydrographic survey vessels operated by the Royal Australian Navy (RAN). Leeuwin and Melville were ordered from NQEA Australia in 1996, and were commissioned in 2000. The ships are capable of charting waters up to 6,000 metres (20,000 ft) deep, carry three Fantome-class survey boats, and can operate an AS 350B Squirrel helicopter. In addition to surveying duties, since 2001 both vessels have been used to supplement the RAN patrol force. Leeuwin and Melville are based at HMAS Cairns, and are active as of 2019.
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.
HMAS Melville is the second ship of the Leeuwin class of hydrographic survey vessels operated by the Royal Australian Navy (RAN).
The Fantome class is a class of eight small survey motor boats (SMBs) operated by the Royal Australian Navy (RAN) and DMS Maritime. The four-man boats are designed to operate from the Leeuwin-class survey vessels, with three assigned to each ship, while the seventh and eighth were attached to the RAN Hydrographic School at HMAS Penguin. They are fitted with navigational and survey equipment and are unarmed.
The Sandhayak-class survey ships are a series of eight vessels built by Garden Reach Shipbuilders and Engineers (GRSE), Kolkata and Goa Shipyard, Ltd., Vasco for the Indian Navy. While Sandhayak, Investigator, Nirdeshak, Nirupak were built in GRSE; Sarveshak, Jamuna, Darshak, Sutlej were built by Goa Shipyard. The vessels equipped with four survey motor boats, two small boats and are powered by two diesel engines with a top speed of 16 knots. They have a helicopter deck and are also armed with a Bofors 40 mm/60 gun mount for self-defense.
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.
Alliance (A5345) is a research vessel owned by NATO and operated by the Marina Militare as a NATO research vessel and owned by the CMRE – Centre for Maritime Research and Experimentation, in La Spezia, Italy. Alliance has the status of an auxiliary ship of the Marina Militare.
The Ninfe class of survey vessels consists of two catamaran hulls operated by the Marina Militare Italiana.
USSP is a planned Submarine rescue ship of the Marina Militare, financed with 2017's balance law.
It is expected to replace Italian ship Anteo.
UIOM is a planned ocean-going Hydrographic survey vessel of the Marina Militare to be replace Italian ship Ammiraglio Magnaghi (A5303) from 2020
INS Nirdeshak (J19)(Hindi: निर्देशक lit. director) was the sixth ship of the Sandhayak class of the Indian Navy. The ship operated as a hydrographic survey ship in the Indian Navy, under the Eastern Naval Command. Nirdeshak was equipped to prepare a variety of marine charts and maps for ECDIS system. The ship's secondary role was to conduct humanitarian aid and disaster management operations, wherein the ship could be converted into a hospital ship. The ship was also equipped with an operating theater and associated equipment needed to attend to medical emergencies at sea.
Italy
