Search results
Results from the WOW.Com Content Network
Vertical datums in Europe. 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.
A vertical datum is used to measure the elevation or depth relative to a standard origin, such as mean sea level (MSL). A three-dimensional datum enables the expression of both horizontal and vertical position components in a unified form. [2] The concept can be generalized for other celestial bodies as in planetary datums.
Vertical measurements, based on distances above or below Mean High Water (MHW), are calculated using the North American Vertical Datum of 1988 (NAVD 88). [ 1 ] NAD 83, along with NAVD 88, is set to be replaced with a new GPS - and gravimetric geoid model-based geometric reference frame and geopotential datum, potentially in 2025 .
A vertical datum is used to measure the elevation or depth relative to a standard origin, such as mean sea level (MSL). A three-dimensional datum enables the expression of both horizontal and vertical position components in a unified form. [2] The concept can be generalized for other celestial bodies as in planetary datums. City of Chicago ...
A geodetic datum (horizontal, vertical, or three-dimensional) which binds the abstract coordinate system to the real space of the Earth. A horizontal datum can be defined as a precise reference framework for measuring geographic coordinates (latitude and longitude). Examples include the World Geodetic System and the 1927 and 1983 North American ...
European Datum 1950: SAD69: South American Datum 1969: GRS 80: Geodetic Reference System 1980: ISO 6709: Geographic point coord. 1983: NAD 83: North American Datum 1983: WGS 84: World Geodetic System 1984: NAVD 88: N. American Vertical Datum 1988: ETRS89: European Terrestrial Ref. Sys. 1989: GCJ-02: Chinese obfuscated datum 2002: Geo URI ...
A horizonal datum is used to precisely measure latitude and longitude, while a vertical datum is used to measure elevation or altitude. Both types of datum bind a mathematical model of the shape of the earth (usually a reference ellipsoid for a horizontal datum, and a more precise geoid for a vertical datum) to the
Common chart datums are lowest astronomical tide (LAT) [1] and mean lower low water (MLLW). In non-tidal areas, e.g. the Baltic Sea, mean sea level (MSL) is used. [2] A chart datum is a type of vertical datum and must not be confused with the horizontal datum for the chart.