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Research vessel
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A research vessel is a ship or boat designed, modified, and/or equipped to carry out research at sea. Research vessels carry out a number of roles, some of these roles can be combined into a single vessel but others require a dedicated vessel. Due to the nature of the work, research vessels are often constructed around an icebreaker hull. The research ship had origins in the voyages of exploration. By the time of James Cooks Endeavour, the essentials of what today we would call a ship are clearly apparent. In 1766, the Royal Society hired Cook to travel to the Pacific Ocean to observe, the Endeavour was a sturdy boat, well designed and equipped for the ordeals she would face, and fitted out with facilities for her research personnel, Joseph Banks. And, as is common with contemporary research vessels, Endeavour carried out more than one kind of research, some other notable early research vessels were HMS Beagle, RV Calypso, HMS Challenger, USFC Albatross, and the Endurance and Terra Nova. The names of early research vessels have been used to later research vessels. A hydrographic survey ship is a designed to conduct hydrographic research. Nautical charts are produced from this information to ensure safe navigation by military, hydrographic survey vessels also conduct seismic surveys of the seabed and the underlying geology. Apart from producing the charts, this information is useful for detecting geological features which are likely to bear oil or gas, in practice, hydrographic survey vessels are often equipped to perform multiple roles. Some function also as oceanographic research ships, naval hydrographic survey vessels often do naval research, for example, on submarine detection. An example of a survey vessel is CCGS Frederick G. Creed. For an example of the employment of a survey ship see HMS Hydra and these vessels often also carry scientific divers and unmanned underwater vehicles. Since the requirements of both oceanographic and hydrographic research are very different from those of fisheries research, these boats often fulfill dual roles, examples of an oceanographic research vessel include the NOAAS Ronald H. Brown and the Chilean Navy Cabo de Hornos. An example of a research vessel is FRV Scotia. Naval research vessels investigate naval concerns, such as submarine and mine detection, sonar, an example of a naval research vessel is the Planet of the German Navy. Polar research vessels are constructed around a hull, allowing them to operate in polar waters
2.
Global Positioning System
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The Global Positioning System is a space-based radionavigation system owned by the United States government and operated by the United States Air Force. The GPS system operates independently of any telephonic or internet reception, the GPS system provides critical positioning capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, however, the US government can selectively deny access to the system, as happened to the Indian military in 1999 during the Kargil War. The U. S. Department of Defense developed the system and it became fully operational in 1995. Roger L. Easton of the Naval Research Laboratory, Ivan A, getting of The Aerospace Corporation, and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it. Announcements from Vice President Al Gore and the White House in 1998 initiated these changes, in 2000, the U. S. Congress authorized the modernization effort, GPS III. In addition to GPS, other systems are in use or under development, mainly because of a denial of access. The Russian Global Navigation Satellite System was developed contemporaneously with GPS, GLONASS can be added to GPS devices, making more satellites available and enabling positions to be fixed more quickly and accurately, to within two meters. There are also the European Union Galileo positioning system and Chinas BeiDou Navigation Satellite System, special and general relativity predict that the clocks on the GPS satellites would be seen by the Earths observers to run 38 microseconds faster per day than the clocks on the Earth. The GPS calculated positions would quickly drift into error, accumulating to 10 kilometers per day, the relativistic time effect of the GPS clocks running faster than the clocks on earth was corrected for in the design of GPS. The Soviet Union launched the first man-made satellite, Sputnik 1, two American physicists, William Guier and George Weiffenbach, at Johns Hopkinss Applied Physics Laboratory, decided to monitor Sputniks radio transmissions. Within hours they realized that, because of the Doppler effect, the Director of the APL gave them access to their UNIVAC to do the heavy calculations required. The next spring, Frank McClure, the deputy director of the APL, asked Guier and Weiffenbach to investigate the inverse problem — pinpointing the users location and this led them and APL to develop the TRANSIT system. In 1959, ARPA also played a role in TRANSIT, the first satellite navigation system, TRANSIT, used by the United States Navy, was first successfully tested in 1960. It used a constellation of five satellites and could provide a navigational fix approximately once per hour, in 1967, the U. S. Navy developed the Timation satellite, which proved the feasibility of placing accurate clocks in space, a technology required by GPS. In the 1970s, the ground-based OMEGA navigation system, based on comparison of signal transmission from pairs of stations. Limitations of these systems drove the need for a more universal navigation solution with greater accuracy, during the Cold War arms race, the nuclear threat to the existence of the United States was the one need that did justify this cost in the view of the United States Congress. This deterrent effect is why GPS was funded and it is also the reason for the ultra secrecy at that time
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Magnetometer
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A compass is a simple example of a magnetometer, one that measures the direction of an ambient magnetic field. Magnetometers are widely used for measuring the Earths magnetic field and in geophysical surveys to detect anomalies of various types. They are also used in the military to detect submarines, consequently, some countries, such as the United States, Canada and Australia, classify the more sensitive magnetometers as military technology, and control their distribution. Magnetic fields are vector quantities characterized by strength and direction. The strength of a field is measured in units of tesla in the SI units. 10,000 gauss are equal to one tesla, measurements of the Earths magnetic field are often quoted in units of nanotesla, also called a gamma. Gaussmeters and teslameters are magnetometers that measure in units of gauss or tesla, in some contexts, magnetometer is the term used for an instrument that measures fields of less than 1 millitesla and gaussmeter is used for those measuring greater than 1 mT. There are two types of magnetometer measurement. Vector magnetometers measure the components of a magnetic field. Total field magnetometers or scalar magnetometers measure the magnitude of the magnetic field. Magnetometers used to study the Earths magnetic field may express the components of the field in terms of declination. Absolute magnetometers measure the magnitude or vector magnetic field, using an internal calibration or known physical constants of the magnetic sensor. Relative magnetometers measure magnitude or vector magnetic field relative to a fixed but uncalibrated baseline, also called variometers, relative magnetometers are used to measure variations in magnetic field. Magnetometers may also be classified by their situation or intended use, stationary magnetometers are installed to a fixed position and measurements are taken while the magnetometer is stationary. Portable or mobile magnetometers are meant to be used while in motion, laboratory magnetometers are used to measure the magnetic field of materials placed within them and are typically stationary. The performance and capabilities of magnetometers are described through their technical specifications, major specifications include Sample rate is the amount of readings given per second. The inverse is the time in seconds per reading. Sample rate is important in mobile magnetometers, the sample rate, bandwidth or bandpass characterizes how well a magnetometer tracks rapid changes in magnetic field
4.
Oceanography
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Oceanography, also known as oceanology, is the study of the physical and the biological aspects of the ocean. Paleoceanography studies the history of the oceans in the geologic past, humans first acquired knowledge of the waves and currents of the seas and oceans in pre-historic times. Observations on tides were recorded by Aristotle and Strabo, early exploration of the oceans was primarily for cartography and mainly limited to its surfaces and of the animals that fishermen brought up in nets, though depth soundings by lead line were taken. Although Juan Ponce de León in 1513 first identified the Gulf Stream, Franklin measured water temperatures during several Atlantic crossings and correctly explained the Gulf Streams cause. Franklin and Timothy Folger printed the first map of the Gulf Stream in 1769-1770, information on the currents of the Pacific Ocean was gathered by explorers of the late 18th century, including James Cook and Louis Antoine de Bougainville. James Rennell wrote the first scientific textbooks on oceanography, detailing the current flows of the Atlantic, during a voyage around the Cape of Good Hope in 1777, he mapped the banks and currents at the Lagullas. He was also the first to understand the nature of the intermittent current near the Isles of Scilly, Robert FitzRoy published a four-volume report of the Beagles three voyages. In 1841–1842 Edward Forbes undertook dredging in the Aegean Sea that founded marine ecology, the first superintendent of the United States Naval Observatory, Matthew Fontaine Maury devoted his time to the study of marine meteorology, navigation, and charting prevailing winds and currents. His 1855 textbook Physical Geography of the Sea was one of the first comprehensive oceanography studies, many nations sent oceanographic observations to Maury at the Naval Observatory, where he and his colleagues evaluated the information and distributed the results worldwide. Despite all this, human knowledge of the oceans remained confined to the topmost few fathoms of the water, almost nothing was known of the ocean depths. The Royal Navys efforts to all of the worlds coastlines in the mid-19th century reinforced the vague idea that most of the ocean was very deep. As exploration ignited both popular and scientific interest in the regions and Africa, so too did the mysteries of the unexplored oceans. The seminal event in the founding of the science of oceanography was the 1872-76 Challenger expedition. As the first true oceanographic cruise, this laid the groundwork for an entire academic. In response to a recommendation from the Royal Society, The British Government announced in 1871 an expedition to explore worlds oceans, charles Wyville Thompson and Sir John Murray launched the Challenger expedition. The Challenger, leased from the Royal Navy, was modified for scientific work, under the scientific supervision of Thomson, Challenger travelled nearly 70,000 nautical miles surveying and exploring. On her journey circumnavigating the globe,492 deep sea soundings,133 bottom dredges,151 open water trawls and 263 serial water temperature observations were taken, around 4,700 new species of marine life were discovered. The result was the Report Of The Scientific Results of the Exploring Voyage of H. M. S, Murray, who supervised the publication, described the report as the greatest advance in the knowledge of our planet since the celebrated discoveries of the fifteenth and sixteenth centuries
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Hydrography
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The origins of hydrography lay in the making of charts to aid navigation, by individual mariners as they navigated into new waters. These were usually the property, even closely held secrets. National organizations, particularly navies, realized that the collection, systematization and distribution of this gave it great organizational. Thus were born dedicated national hydrographic organizations for the collection, organization, publication and distribution of hydrography incorporated into charts, prior to the establishment of the United Kingdom Hydrographic Office, Royal Navy captains were responsible for the provision of their own charts. In practice this meant that ships often sailed with inadequate information for safe navigation, and that when new areas were surveyed, the Admiralty appointed Alexander Dalrymple as Hydrographer in 1795, with a remit to gather and distribute charts to HM Ships. Within a year existing charts from the two centuries had been collated, and the first catalogue published. The first chart produced under the direction of the Admiralty, was a chart of Quiberon Bay in Brittany, under Captain Thomas Hurd the department received its first professional guidelines and the first catalogues were published and made available to the public and to other nations as well. In 1829, Rear-Admiral Sir Francis Beaufort, as Hydrographer, developed the eponymous Scale, and introduced the first official tide tables in 1833, the word hydrography comes from the Ancient Greek ὕδωρ, water and γράφω, to write. The science of oceanography is, in part, an outgrowth of classical hydrography, in many respects the data are interchangeable, but marine hydrographic data will be particularly directed toward marine navigation and safety of that navigation. Marine resource exploration and exploitation is a significant application of hydrography, hydrographical measurements include the tidal, current and wave information of physical oceanography. Bottom measurements also include collection of the nature of the bottom as it pertains to effective anchoring, unlike oceanography, hydrography will include shore features, natural and manmade, that aid in navigation. Hydrography, mostly for reasons of safety, adopted a number of conventions that have affected its portrayal of the data on nautical charts, the former are the mariners tools to avoid accident. The latter are best representations of the seabed, as in a topographic map, for scientific. Trends in hydrographic practice since c, 2003–2005 have led to a narrowing of this difference, with many more hydrographic offices maintaining best observed databases, and then making navigationally safe products as required. This has been coupled with a preference for multi-use surveys, so that the data collected for nautical charting purposes can also be used for bathymetric portrayal. For instance, if there is an area that can not be reached because it is surrounded by shallow water. The color filled areas that show different ranges of water are not the equivalent of contours on a topographic map since they are often drawn seaward of the actual shallowest depth portrayed. A bathymetric chart does show marine topology accurately, details covering the above limitations can be found in Part 1 of Bowditchs American Practical Navigator
6.
Multibeam echosounder
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A multibeam echosounder is a type of sonar that is used to map the seabed. Like other sonar systems, multibeam systems emit sound waves in a fan shape beneath a ships hull, the amount of time it takes for the sound waves to bounce off the seabed and return to a receiver is used to determine water depth. Unlike other sonars, multibeam systems use beamforming to extract information from the returning soundwaves. Multibeam sonar sounding systems, also known as swathe or swath, SASS was tested aboard the USS Compass Island. The final array system, composed of one degree beams with a swath width of approximately 1.15 times water depth, was then installed on the USNS Bowditch, USNS Dutton. The first commercial multibeam is now known as the SeaBeam Classic and was put in service in May 1977 on the Australian survey vessel HMAS Cook and this system produced up to 16 beams across a 45-degree arc. The term SeaBeam Classic was coined after the manufacturer developed newer systems such as the SeaBeam 2000, the second SeaBeam Classic installation was on the French Research Vessel Jean Charcot. The SB Classic arrays on the Charcot were damaged in a grounding, although it seems that the original SeaBeam Classic installation was not used much, the others were widely used, and subsequent installations were made on many vessels. SeaBeam Classic systems were installed on the US academic research vessels USNS Thomas Washington, the USNS Robert D. Conrad. Multibeam echosounders are commonly used for geological and oceanographic research. In 1989, Atlas Electronics installed a second-generation deep-sea multibeam called Hydrosweep DS on the German research vessel Meteor, the Hydrosweep DS produced up to 59 beams across a 90-degree swath, which was a vast improvement and was inherently ice-strengthened. As the cost of components has decreased, the number of systems sold. Smaller, portable systems can be operated on a launch or tender vessel unlike the older systems that required considerable time. Some multibeam echosounders such as the Teledyne Odom ES3 also incorporate a motion sensor at the face of the acoustic transducer, multibeam echosounders like this are allowing many smaller hydrographic survey companies to move from traditional single beam echosounders to swath systems. Multibeam data includes bathymetry, acoustic backscatter, and water column data, gas plumes now commonly identified in midwater multibeam data are termed flares. A multibeam echosounder is a device used by hydrographic surveyors to determine the depth of water. From this narrow beam a two way travel time of the pulse is then established utilizing a bottom detection algorithm. If the speed of sound in water is known for the water column profile, the depth and position of the return signal can be determined from the receive angle
7.
Side-scan sonar
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Side-scan sonar is a category of sonar system that is used to efficiently create an image of large areas of the sea floor. 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 used for fisheries research, dredging operations. It also has applications including mine detection. The intensity of the reflections from the seafloor of this fan-shaped beam is recorded in a series of cross-track slices. When stitched together along the direction of motion, these form an image of the sea bottom within the swath of the beam. The sound frequencies used in side-scan sonar usually range from 100 to 500 kHz, higher frequencies yield better resolution, the earliest side-scan sonars used a single conical-beam transducer. Next, units were made with two transducers to cover both sides, the transducers were either contained in one hull-mounted package or with two packages on either side of the vessel. Next the transducers evolved to fan-shaped beams to produce a better sonogram or sonar image, in order to get closer to the bottom in deep water the side-scan transducers were placed in a towfish and pulled by a tow cable. Up until the mid-1980s, commercial sidescan images were produced on paper records, the early paper records were produced with a sweeping plotter that burned the image into a scrolling paper record. Later plotters allowed for the plotting of position and ship motion information onto the paper record. Currently data is stored on hard drives or solid-state media. His work is documented in US Patent 4,197,591 which was first disclosed in Aug 1958, experimental side-scan sonar systems were made during the 1950s in laboratories including Scripps Institution of Oceanography and Hudson Laboratories and by Dr. Harold Edgerton at MIT. Military side-scan sonars were made in the 1950s by Westinghouse and this group also produced the first and only working Angle Look Sonar that could trace objects while looking under the vehicle. The first commercial system was the Kelvin Hughes Transit Sonar. In 1963 Dr. Harold Edgerton, Edward Curley, and John Yules used a conical-beam 12 kHz side-scan sonar to find the sunken Vineyard Lightship in Buzzards Bay, Massachusetts. A team led by Martin Klein at Edgerton, Germeshausen & Grier developed the first successful towed, Martin Klein is generally considered to be the father of commercial side-scan sonar. In 1967, Edgerton used Kleins sonar to help Alexander McKee find Henry VIIIs flagship Mary Rose and that same year Klein used the sonar to help archaeologist George Bass find a 2000-year-old ship off the coast of Turkey
8.
Benthic zone
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The benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Organisms living in this zone are called benthos, e. g. the benthic community, including crustaceans. The organisms generally live in relationship with the substrate bottom. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, the benthic region of the ocean begins at the shore line and extends downward along the surface of the continental shelf out to sea. The continental shelf is a gently sloping benthic region that extends away from the land mass, at the continental shelf edge, usually about 200 meters deep, the gradient greatly increases and is known as the continental slope. The continental slope drops down to the sea floor. The deep-sea floor is called the plain and is usually about 4,000 meters deep. The ocean floor is not all flat but has submarine ridges, for comparison, the pelagic zone is the descriptive term for the ecological region above the benthos, including the water-column up to the surface. For information on animals that live in the areas of the oceans see aphotic zone. Generally, these life forms that tolerate cool temperatures and low oxygen levels. Benthos are the organisms live in the benthic zone, and are different from those elsewhere in the water column. Many are adapted to live on the substrate, in their habitats they can be considered as dominant creatures, but they are often a source of prey for Carcharhinidae such as the lemon shark. Many organisms adapted to deep-water pressure cannot survive in the parts of the water column. The pressure difference can be very significant, because light does not penetrate very deep into ocean-water, the energy source for the benthic ecosystem is often organic matter from higher up in the water column that drifts down to the depths. This dead and decaying matter sustains the benthic food chain, most organisms in the zone are scavengers or detritivores. Some microorganisms use chemosynthesis to produce biomass, Benthic organisms can be divided into two categories based on whether they make their home on the ocean floor or an inch or two into the ocean floor. Those living on the surface of the floor are known as epifauna. Those who live burrowed into the floor are known as infauna
