An ordnance datum (OD) is a vertical datum used by an ordnance survey as the basis for deriving altitudes on maps. A spot height may be expressed as above...

NAP markers in Amsterdam Amsterdam Ordnance Datum or Normaal Amsterdams Peil (NAP) is a vertical datum in use in large parts of Western Europe. Originally...

square to the north of 49 is N40, etc. The grid is based on the OSGB36 datum (Ordnance Survey Great Britain 1936, based on the Airy 1830 ellipsoid), and was...

shells Aircraft ordnance, weapons carried by and used by an aircraft Ordnance, Oregon, United States Ordnance Island, Bermuda Ordnance datum (from use in...

A geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame, or terrestrial reference frame)...

In geodesy, surveying, hydrography and navigation, vertical datum or altimetric datum is a reference coordinate surface used for vertical positions, such...

the land on which the tide gauge operates, or both. In the UK, the ordnance datum (the 0 metres height on UK maps) is the mean sea level measured at Newlyn...

The North American Vertical Datum of 1988 (NAVD 88) is the vertical datum for orthometric heights established for vertical control surveying in the United...

recorded beside it that represents its height above a given datum. In the UK this is the Ordnance Datum. Unlike a bench-mark, which is marked by a disc or plate...

a width of 90 metres (300 ft), at an initial height above Amsterdam Ordnance Datum of between 6.7 metres (22 ft) along the section at Friesland, and 7...

of) national mapping agencies Ordnance datum (sea level) Ordnance Survey International Ordnance Survey Ireland Ordnance Survey of Northern Ireland Romer...

Broad arrow Geoid Levelling—a surveying technique that uses benchmarks Ordnance datum Spot height "Bench marks and levelling points". Heritage and History...

diameter (also: O.D.), cylinder or pipe external diameter Ordnance datum, in Britain, an Ordnance Survey data point od (Unix), a Unix program Object Desktop...

The North American Datum (NAD) is the horizontal datum now used to define the geodetic network in North America. A datum is a formal description of the...

massif itself is Pen Pumlumon Fawr, which is 752 metres (2,467 ft) above ordnance datum. Its other important peaks are Pen Pumlumon Arwystli, Y Garn, Pen Pumlumon...

of the River Thames to reach a maximum height of 14.5 metres (48 ft) Ordnance Datum. The land was historically part of the Liberties of the Tower of London...

changed its height system over to normal heights based on the datum of the Amsterdam Ordnance Datum, known as the German Mean Height Reference System, DHHN92...

the lowest point of the Netherlands: 6.76 m (22.2 ft) below Amsterdam Ordnance Datum (mean summer sea level in Amsterdam). It is the hometown of Miss Universe...

through; in 1953 a large storm, measured at 5.12 m (16.8 ft) above ordnance datum (see North Sea flood of 1953) hit the North Norfolk coast and the shingle...

drift. The development of ETRS89 is related to the global ITRS geodetic datum, in which the representation of the continental drift is balanced in such...

The levels are regulated between 12.45 metres and 12.6 metres above Ordnance Datum, as defined in the Lough Neagh (Levels) Scheme 1955 (as amended). The...

English Heritage. The accessible hill fort, at 160 metres (520 ft) ordnance datum, gives panoramic views across North and Mid Wales, Cheshire and Shropshire...

Ouse’s normal water level at York is approximately 5 metres AOD (Above Ordnance Datum). When the river level reaches 7.5 metres AOD, the barrier is lowered...

standards, also includes a choice of geodetic datum (including an Earth ellipsoid), as different datums will yield different latitude and longitude values...

observatory between 1915 and 1921 were used to define the reference level, Ordnance Datum Newlyn, for height measurement on the British mainland. The tide gauge...

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...

the lowest point on the Dutch polders, 7.01 meters below Amsterdam Ordnance Datum. The first reference to the area is from 1233, when on April 20, Floris...

level, or rather below Normaal Amsterdams Peil (NAP) or 'Amsterdam Ordnance Datum'. The lowest point in the Netherlands (6.76 m (22.2 ft) below NAP) is...

river entrance, which was closed in 1846. Between 1844 and 1921, the Ordnance Datum for the British Isles was taken from the level of the Victoria Dock...

referenced to the same geodetic datum. A geographic coordinate transformation is a translation among different geodetic datums. Both geographic coordinate...