• Thumbnail for Ordnance datum
    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...
    7 KB (777 words) - 11:01, 5 February 2025
  • Thumbnail for Amsterdam Ordnance Datum
    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...
    4 KB (434 words) - 13:20, 18 February 2025
  • Thumbnail for Vertical datum
    In geodesy, surveying, hydrography and navigation, vertical datum or altimetric datum is a reference coordinate surface used for vertical positions, such...
    11 KB (1,470 words) - 10:36, 3 February 2025
  • Thumbnail for Geodetic datum
    A geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame, or terrestrial reference frame)...
    32 KB (3,376 words) - 19:59, 18 February 2025
  • Thumbnail for Ordnance Survey National Grid
    49 is N40, etc. The grid is based on the OSGB36 datum (Ordnance Survey Great Britain 1936). The datum was introduced after the retriangulation of 1936–1962...
    19 KB (2,175 words) - 00:51, 13 March 2025
  • Thumbnail for Afsluitdijk
    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...
    24 KB (2,718 words) - 20:13, 7 April 2025
  • shells Aircraft ordnance, weapons carried by and used by an aircraft Ordnance, Oregon, United States Ordnance Island, Bermuda Ordnance datum (from use in...
    723 bytes (106 words) - 01:45, 23 May 2023
  • Thumbnail for Ordnance Survey
    of) national mapping agencies Ordnance datum (sea level) Ordnance Survey International Ordnance Survey Ireland Ordnance Survey of Northern Ireland Romer...
    84 KB (8,629 words) - 21:23, 1 April 2025
  • Thumbnail for Benchmark (surveying)
    Broad arrow Geoid Levelling—a surveying technique that uses benchmarks Ordnance datum Spot height "Bench marks and levelling points". Heritage and History...
    10 KB (1,053 words) - 15:42, 10 February 2025
  • Thumbnail for 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...
    7 KB (730 words) - 03:18, 4 February 2025
  • Thumbnail for North American Datum
    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...
    13 KB (1,634 words) - 03:57, 20 November 2024
  • Thumbnail for Tower Hill
    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...
    20 KB (1,976 words) - 03:22, 10 April 2025
  • Thumbnail for Sea level
    Sea level (category Vertical datums)
    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...
    21 KB (3,921 words) - 17:07, 12 March 2025
  • Thumbnail for Spot height
    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...
    1 KB (113 words) - 07:56, 1 April 2023
  • Thumbnail for European Terrestrial Reference System 1989
    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...
    6 KB (615 words) - 22:40, 28 February 2025
  • Thumbnail for Geographic coordinate system
    standards, also includes a choice of geodetic datum (including an Earth ellipsoid), as different datums will yield different latitude and longitude values...
    23 KB (2,496 words) - 17:33, 10 April 2025
  • Thumbnail for Elevation
    of 1/3, 1, and 2 arcseconds. Amsterdam Ordnance Datum, a.k.a. Normaal Amsterdams Peil (NAP), Dutch vertical datum Elevation profile Geodesy GTOPO30 a digital...
    6 KB (561 words) - 15:40, 18 November 2024
  • directions See intercardinal directions. ordnance datum (OD) Any vertical datum used by the British Ordnance Survey as the basis for reporting elevations...
    212 KB (20,255 words) - 13:29, 7 April 2025
  • Thumbnail for Newlyn Tidal Observatory
    Newlyn Tidal Observatory (category Vertical datums)
    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...
    10 KB (866 words) - 06:39, 2 April 2025
  • referenced to the same geodetic datum. A geographic coordinate transformation is a translation among different geodetic datums. Both geographic coordinate...
    34 KB (5,200 words) - 08:18, 10 August 2024
  • Thumbnail for Waddinxveen
    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...
    7 KB (367 words) - 12:43, 3 April 2025
  • Thumbnail for Normalhöhennull
    Normalhöhennull (category Vertical datums)
    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...
    6 KB (572 words) - 00:08, 23 July 2024
  • Thumbnail for Plynlimon
    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...
    7 KB (588 words) - 23:48, 5 April 2025
  • Thumbnail for Water levels of the Birmingham Canal Navigations
    given are nominal elevation above sea level in feet relative to the Ordnance Datum Liverpool. A former branch of the Wyrley and Essington Canal, the Essington...
    7 KB (824 words) - 14:45, 11 December 2022
  • Thumbnail for River Bann
    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...
    24 KB (2,765 words) - 02:00, 3 March 2025
  • Thumbnail for Nieuwerkerk aan den IJssel
    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...
    4 KB (314 words) - 15:47, 24 September 2024
  • 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...
    3 KB (454 words) - 20:02, 21 February 2025
  • making Automatic Overdrive transmission, a vehicle transmission Above Ordnance Datum, a level expressed as a height above mean sea level Adult Onset Diabetes...
    2 KB (345 words) - 01:09, 24 November 2024
  • Thumbnail for Old Oswestry
    English Heritage. The accessible hill fort, at 160 metres (520 ft) ordnance datum, gives panoramic views across North and Mid Wales, Cheshire and Shropshire...
    9 KB (776 words) - 18:39, 14 February 2025
  • Thumbnail for Bibury
    is 300 metres (330 yd) from the village, 151 metres (495 ft) above Ordnance Datum (AOD), which is a similar elevation to much of the north. The south...
    20 KB (1,797 words) - 05:20, 3 April 2025