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Hydrographic Surveys
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. Hydrography is collected under rules which vary depending on the acceptance authority. Traditionally conducted by ships with a sounding line or echo sounding, surveys are increasingly conducted with the aid of aircraft and sophisticated electronic sensor systems in shallow waters. Organizations National and International Maritime Hydrography Hydrographic offices evolved from n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Exploration
Hydrocarbon exploration (or oil and gas exploration) is the search by petroleum geologists and geophysicists for deposits of hydrocarbons, particularly petroleum and natural gas, in the Earth using petroleum geology. Exploration methods Visible surface features such as oil seeps, natural gas seeps, pockmarks (underwater craters caused by escaping gas) provide basic evidence of hydrocarbon generation (be it shallow or deep in the Earth). However, most exploration depends on highly sophisticated technology to detect and determine the extent of these deposits using exploration geophysics. Areas thought to contain hydrocarbons are initially subjected to a gravity survey, magnetic survey, passive seismic or regional seismic reflection surveys to detect large-scale features of the sub-surface geology. Features of interest (known as ''leads'') are subjected to more detailed seismic surveys which work on the principle of the time it takes for reflected sound waves to travel th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USC&GS Hilgard (ASV 82)
USC&GS ''Hilgard'' (ASV 82).Silverstone, Paul H.''The Navy of the Nuclear Age 1947-2007'' New York: Routledge, 2009, , p. 303. was a survey ship that served in the United States Coast and Geodetic Survey from 1942 to 1967. ''Hilgard'' was built as an "auxiliary survey vessel" (ASV) for the Coast and Geodetic Survey by Robinson Marine at Benton Harbor, Michigan, in 1942. ''Hilgard'' and her sister ship USC&GS ''Wainwright'' (ASV 83) conducted wire-drag hydrographic survey operations together along the United States East Coast The East Coast of the United States, also known as the Eastern Seaboard, the Atlantic Coast, and the Atlantic Seaboard, is the coastline along which the Eastern United States meets the North Atlantic Ocean. The eastern seaboard contains the coa ... until 1967, when they were replaced by USC&GS ''Rude'' (ASV 90), which later became NOAAS ''Rude'' (S 590), and USC&GS ''Heck'' (ASV 91), which later became NOAAS ''Heck'' (S 591). See also * Other ship ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USC&GS Ogden
USC&GS ''Ogden'' was a launch that served as a survey ship in the United States Coast and Geodetic Survey from 1919 to 1944. She was the only Coast and Geodetic Survey ship to bear the name. ''Ogden'' was built by the Canton Lumber Company at Baltimore, Maryland, in 1919. She entered Coast and Geodetic Survey service that year. ''Ogden'' spent her career on the United States East Coast. She worked as a wire-drag hydrographic survey 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 ... vessel with the Coast and Geodetic Survey launch USC&GS ''Marindin''. ''Ogden'' was retired from Coast and Geodetic Survey service in 1944. ReferencesNOAA History, A Science Odyssey: Tools of the Trade: Ships: Coast and Geodetic Survey Ships: Ogden {{DEFAULTSORT:Ogden (1919) Ships of the Unite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USC&GS Marindin
USC&GS ''Marindin'' was a launch that served as a survey ship in the United States Coast and Geodetic Survey from 1919 to 1944. She was the only Coast and Geodetic Survey ship to bear the name. ''Marindin'' was built by the Canton Lumber Company at Baltimore, Maryland, in 1919. She entered Coast and Geodetic Survey service that year. ''Marindin'' spent her career on the United States East Coast. She worked as a wire-drag hydrographic survey vessel with the Coast and Geodetic Survey launch USC&GS ''Ogden''. On 10–11 December 1924, ''Marindin'' and the Coast and Geodetic survey launch USC&GS ''Mitchell'' aided a United States Marine Corps motor sailer that had gone aground by pulling it off the rocks and towing it to the U.S. Marine Corps boathouse at St. Thomas in the United States Virgin Islands. On 28 June 1922, she joined the Coast and Geodetic Survey survey ship USC&GS ''Ranger'' in searching for survivors of the schooner ''Rose Standish'', which had burned off ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Ship
A sister ship is a ship of the same class or of virtually identical design to another ship. Such vessels share a nearly identical hull and superstructure layout, similar size, and roughly comparable features and equipment. They often share a common naming theme, either being named after the same type of thing or person (places, constellations, heads of state) or with some kind of alliteration. Typically the ship class is named for the first ship of that class. Often, sisters become more differentiated during their service as their equipment (in the case of naval vessels, their armament) are separately altered. For instance, the U.S. warships , , , and are all sister ships, each being an . Perhaps the most famous sister ships were the White Star Line's s, consisting of , and . As with some other liners, the sisters worked as running mates. Other sister ships include the Royal Caribbean International's and . ''Half-sister'' refers to a ship of the same class but with some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidescan Sonar
Side-scan sonar (also sometimes called side scan sonar, sidescan sonar, side imaging sonar, side-imaging sonar and bottom classification sonar) is a category of sonar system that is used to efficiently create an image of large areas of the sea floor. Uses Side-scan sonar may be used to conduct surveys for marine archaeology; in conjunction with seafloor samples it is able to provide an understanding of the differences in material and texture type of the seabed. Side-scan sonar imagery is also a commonly used tool to detect debris items and other obstructions on the seafloor that may be hazardous to shipping or to seafloor installations by the oil and gas industry. In addition, the status of pipelines and cables on the seafloor can be investigated using side-scan sonar. Side-scan data are frequently acquired along with bathymetric soundings and sub-bottom profiler data, thus providing a glimpse of the shallow structure of the seabed. Side-scan sonar is also used for fisheries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicholas H
Nicholas is a male given name and a surname. The Eastern Orthodox Church, the Roman Catholic Church, and the Anglican Churches celebrate Saint Nicholas every year on December 6, which is the name day for "Nicholas". In Greece, the name and its derivatives are especially popular in maritime regions, as St. Nicholas is considered the protector saint of seafarers. Origins The name is derived from the Greek name Νικόλαος (''Nikolaos''), understood to mean 'victory of the people', being a compound of νίκη ''nikē'' 'victory' and λαός ''laos'' 'people'.. An ancient paretymology of the latter is that originates from λᾶς ''las'' ( contracted form of λᾶας ''laas'') meaning 'stone' or 'rock', as in Greek mythology, Deucalion and Pyrrha recreated the people after they had vanished in a catastrophic deluge, by throwing stones behind their shoulders while they kept marching on. The name became popular through Saint Nicholas, Bishop of Myra in Lycia, the inspir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Coast And Geodetic Survey
The United States Coast and Geodetic Survey (abbreviated USC&GS), known from 1807 to 1836 as the Survey of the Coast and from 1836 until 1878 as the United States Coast Survey, was the first scientific agency of the United States Government. It existed from 1807 to 1970, and throughout its history was responsible for mapping and charting the coast of the United States, and later the coasts of Territories of the United States, U.S. territories. In 1871, it gained the additional responsibility of surveying the interior of the United States and geodesy became a more important part of its work, leading to it being renamed the U.S. Coast and Geodetic Survey in 1878. Long the U.S. Government's only scientific agency, the Survey accumulated other scientific and technical responsibilities as well, including astronomy, cartography, meteorology, geology, geophysics, hydrography, navigation, oceanography, exploration, pilotage, tides, and topography. It also was responsible for the standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means 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 (an upward-looking in-air sonar) 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 extr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echosounder
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. Echo sounding can also be used for ranging to other targets, such as fish schools. Hydroacoustic assessments have traditionally employed mobile surveys from boats to evaluate fish biomass and spatial distributions. Conversely, fixed-location techniques use stationary transducers to monitor passing fish. The word '' sounding'' is used for all types of depth measurements, including those that don't use sound, and is unrelated in origin to the word ''sound'' in the sense of noise or to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sextant
A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of celestial navigation. The estimation of this angle, the altitude, is known as ''sighting'' or ''shooting'' the object, or ''taking a sight''. The angle, and the time when it was measured, can be used to calculate a position line on a nautical or aeronautical chart—for example, sighting the Sun at noon or Polaris at night (in the Northern Hemisphere) to estimate latitude (with sight reduction). Sighting the height of a landmark can give a measure of ''distance off'' and, held horizontally, a sextant can measure angles between objects for a position on a chart. A sextant can also be used to measure the lunar distance between the moon and another celestial object (such as a star or planet) in order to determine Greenwich Mean Time and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
