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Vertical Datum
In geodesy, surveying, hydrography and navigation, vertical datum or altimetric datum is a reference coordinate surface used for vertical positions, such as the elevations of Earth-bound features (terrain, bathymetry, water level, and built structures) and altitudes of satellite orbits and in aviation. In planetary science, vertical datums are also known as zero-elevation surface or zero-level reference. Commonly adopted criteria for a vertical datum include the following approaches: * Tides, based on sea level when specific conditions occur, such as NOAA's National Geodetic Survey-produced tidal datums; * Gravimetric, based on a geoid; or geometric, based on the same Earth ellipsoids that are used in computing a horizontal datum, such as NOAA's planned gravimetric and Global Navigation Satellite Systems (GNSS)-based Datum of 2022 set to be released that year by the National Geodetic Survey. In the United States, prominent vertical datums for professional uses include the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical References In Europe
Vertical is a geometric term of location which may refer to: * Vertical direction, the direction aligned with the direction of the force of gravity, up or down * Vertical (angles), a pair of angles opposite each other, formed by two intersecting straight lines that form an "X" * Interval (music)#Melodic and harmonic, Vertical (music), a musical interval where the two notes sound simultaneously * "Vertical", a type of wine tasting in which different vintages of the same wine type from the same winery are tasted * Vertical Aerospace, stylised as "Vertical", British aerospace manufacturer * Vertical kilometer, a discipline of skyrunning * Vertical market, a market in which vendors offer goods and services specific to an industry * Vertical integration, a management term describing a style of ownership and control Media * Vertical (film), ''Vertical'' (film), a 1967 Soviet movie starring Vladimir Vysotsky * Vertical (Sledge Hammer!), "Vertical" (''Sledge Hammer!''), 1987 television e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOAA
The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with forecasting weather, monitoring oceanic and atmospheric conditions, charting the seas, conducting deep-sea exploration, and managing fishing and protection of marine mammals and endangered species in the US exclusive economic zone. The agency is part of the United States Department of Commerce and is headquartered in Silver Spring, Maryland. History NOAA traces its history back to multiple agencies, some of which are among the earliest in the federal government: * United States Coast and Geodetic Survey, formed in 1807 * Weather Bureau of the United States, formed in 1870 * Bureau of Commercial Fisheries, formed in 1871 (research fleet only) * Coast and Geodetic Survey Corps, formed in 1917 The most direct predecessor of NOAA was the Environmental Science Services Administration (ESSA), into which several existing scientific agencies such as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newlyn
Newlyn () is a seaside town and fishing port in south-west Cornwall, England, United Kingdom.Ordnance Survey: Landranger map sheet 203 ''Land's End'' It is the largest fishing port in England. Newlyn lies on the shore of Mount's Bay and forms a small conurbation with the neighbouring town of Penzance. It is part of the Penzance civil parishes in England, civil parish. The principal industry is fishing, although there are also a variety of yachts and pleasure boats in the harbour, as Newlyn has become a popular holiday destination with pubs and restaurants. Although the parish is now listed under Penzance, there is an electoral ward in separate existence called Mousehole, Newlyn and St Buryan (electoral division), Mousehole, Newlyn and St Buryan. The population as of the 2011 census was 4,432. Toponymy The settlement is recorded as ''Nulyn'' in 1279 and as ''Lulyn'' in 1290, and the name is thought to be derived from the Cornish language, Cornish for ''"pool for a fleet of bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordnance Datum Newlyn
Ordnance may refer to: Military and defense *Materiel in military logistics, including weapons, ammunition, vehicles, and maintenance tools and equipment *Artillery *Artillery shells *Aircraft ordnance, weapons carried by and used by an aircraft Places *Ordnance, Oregon, United States *Ordnance Island, Bermuda Maps-related *Ordnance datum (from use in ballistics), a vertical datum used as the basis for deriving altitudes on maps *Ordnance Survey The Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose (see Artillery, ordnance and surveying), which was to map Scotland in the wake of the Jacobite rising of ..., the national mapping agency for Great Britain See also *Ordnance Corps (other) {{disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Sea Level
A mean is a quantity representing the "center" of a collection of numbers and is intermediate to the extreme values of the set of numbers. There are several kinds of means (or "measures of central tendency") in mathematics, especially in statistics. Each attempts to summarize or typify a given group of data, illustrating the magnitude and sign of the data set. Which of these measures is most illuminating depends on what is being measured, and on context and purpose. The ''arithmetic mean'', also known as "arithmetic average", is the sum of the values divided by the number of values. The arithmetic mean of a set of numbers ''x''1, ''x''2, ..., x''n'' is typically denoted using an overhead bar, \bar. If the numbers are from observing a sample of a larger group, the arithmetic mean is termed the '' sample mean'' (\bar) to distinguish it from the group mean (or expected value) of the underlying distribution, denoted \mu or \mu_x. Outside probability and statistics, a wide rang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or " tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see '' Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Vertical Datum Of 1988
The North American Vertical Datum of 1988 (NAVD 88) is the vertical datum for orthometric heights established for vertical control surveying in the United States based upon the General Adjustment of the North American Datum of 1988. It superseded the National Geodetic Vertical Datum of 1929 (NGVD 29), previously known as the Sea Level Datum of 1929. NAVD 88, along with North American Datum of 1983 (NAD 83), is set to be replaced in 2025 with a Datum of 2022, new geometric reference frame and geopotential datum, based on GPS and gravimetric geoid models. Methodology NAVD 88 was established in 1991 by the minimum-constraint adjustment of observations, adjustment of geodesy, geodetic leveling observations in Canada, the United States, and Mexico. It held fixed the height of the primary tide gauge Benchmark (surveying), benchmark, referenced to the ''International Great Lakes Datum of 1985'' local mean sea level (MSL) height value, at Rimouski, Quebec, Canada. Additional tidal be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Geodetic Vertical Datum Of 1929
The National Geodetic Vertical Datum of 1929 is the official name since 1973 of the vertical datum established for vertical control surveying in the United States of America by the General Adjustment of 1929. Originally known as Sea Level Datum of 1929, NGVD 29 was determined and published by the United States Coast and Geodetic Survey and used to measure the elevation of a point above and depression below mean sea level (MSL). NGVD29 was superseded by the North American Vertical Datum of 1988 ( NAVD 88), based upon reference to a single benchmark (referenced to the new International Great Lakes Datum of 1985 local mean sea level height value), although many cities and U.S. Army Corps of Engineers "legacy" projects with established data continued to use the older datum. Methodology Mean sea level was measured at 26 tide gauges: 21 in the United States and five in Canada. The datum was defined by the observed heights of mean sea level at the 26 tide gauges and by the set of e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Datum Of 2022
The National Spatial Reference System (NSRS), managed by the National Geodetic Survey (NGS), is a coordinate system that includes latitude, longitude, elevation, and other values. The NSRS consists of a National Shoreline, the NOAA CORS Network (a system of Global Positioning System Continuously Operating Reference Stations), a network of permanently marked points, and a set of models that describe dynamic geophysical processes affecting spatial measurements. The system is based on the datums NAD 83 and NAVD 88. In 2025 or 2026, the NSRS will be modernized with a focus on Global Navigation Satellite Systems (GNSS) and geoid use. It will use the following four frames of reference, each representing a tectonic plate: *North American Terrestrial Reference Frame of 2022 (NATRF2022) *Pacific Terrestrial Reference Frame of 2022 (PTRF2022) *Caribbean Terrestrial Reference Frame of 2022 (CTRF2022) *Mariana Terrestrial Reference Frame of 2022 (MTRF2022) Datum of 2022 The North American- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Navigation Satellite Systems
A satellite navigation or satnav system is a system that uses satellites to provide autonomous geopositioning. A satellite navigation system with global coverage is termed global navigation satellite system (GNSS). , four global systems are operational: the United States's Global Positioning System (GPS), Russia's Global Navigation Satellite System (GLONASS), China's BeiDou Navigation Satellite System (BDS), and the European Union's Galileo. Two regional systems are operational: India's NavIC and Japan's QZSS. ''Satellite-based augmentation systems'' (SBAS), designed to enhance the accuracy of GNSS, include Japan's Quasi-Zenith Satellite System (QZSS), India's GAGAN and the European EGNOS, all of them based on GPS. Previous iterations of the BeiDou navigation system and the present Indian Regional Navigation Satellite System (IRNSS), operationally known as NavIC, are examples of stand-alone operating regional navigation satellite systems (RNSS). Satellite navigation devices ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Ellipsoid
An Earth ellipsoid or Earth spheroid is a mathematical figure approximating the Earth's form, used as a reference frame for computations in geodesy, astronomy, and the geosciences. Various different ellipsoids have been used as approximations. It is a spheroid (an ellipsoid of revolution) whose minor axis (shorter diameter), which connects the geographical North Pole and South Pole, is approximately aligned with the Earth's axis of rotation. The ellipsoid is defined by the ''equatorial axis'' () and the ''polar axis'' (); their radial difference is slightly more than 21 km, or 0.335% of (which is not quite 6,400 km). Many methods exist for determination of the axes of an Earth ellipsoid, ranging from meridian arcs up to modern satellite geodesy or the analysis and interconnection of continental geodetic networks. Amongst the different set of data used in national surveys are several of special importance: the Bessel ellipsoid of 1841, the international Hayfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geoid
The geoid ( ) is the shape that the ocean surface would take under the influence of the gravity of Earth, including gravitational attraction and Earth's rotation, if other influences such as winds and tides were absent. This surface is extended through the continents (such as might be approximated with very narrow hypothetical canals). According to Carl Friedrich Gauss, who first described it, it is the "mathematical figure of the Earth", a smooth but irregular surface whose shape results from the uneven distribution of mass within and on the surface of Earth. It can be known only through extensive gravitational measurements and calculations. Despite being an important concept for almost 200 years in the history of geodesy and geophysics, it has been defined to high precision only since advances in satellite geodesy in the late 20th century. The geoid is often expressed as a geoid undulation or geoidal height above a given reference ellipsoid, which is a slightly flattene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
