2023年5月8日 · Compute a GEOID18 geoid height for a single location: The formats below may be used for entering latitude and longitude. Degrees, minutes, and seconds must be separated by spaces.

The National Geodetic Survey has released updated models for transforming heights between ellipsoidal coordinates and physical height systems that relate to water flow.

The geoid is often expressed as a geoid undulation or geoidal height above a given reference ellipsoid, which is a slightly flattened sphere whose equatorial bulge is caused by the planet's rotation. Generally the geoidal height rises where the Earth's material is locally more dense and exerts greater gravitational force than the surrounding areas.

2023年5月16日 · Our Geoid Height Calculator calculates a geoid undulation at a point (s) whose latitude and longitude is specified. This new version (2021-08-18) of our program is designed to use a variety of Earth Gravitational Models and can now calculate heights for multiple points.

2019年9月9日 · To determine geoid heights with the GEOID18 model, download an INTG executable file, as well as at least one data file. You need to select only those data files that cover your region of interest; the program will recognize the available corresponding files .

2025年2月26日 · GEOID18 Web Map for viewing and analyzing the geoid model Web Map by NGS.GIS_noaa

2024年12月17日 · GEOID2022 provides the connection between ellipsoid heights determined with GPS and orthometric heights used for most applications. The spatial resolution of the geoid model is 1 arcminute. The geoid heights, which are in the tide-free system, are with respect to the reference ellipsoid of the Geodetic Reference System 1980 (GRS80) in the ...

It can be used to convert a height above the ellipsoid, h, to the corresponding height above the geoid (the orthometric height, roughly the height above mean sea level), H, using the relations. h = N + H; H = − N + h. GeoidEval, which is a simple wrapper of the GeographicLib::Geoid class, is one of the utilities provided with GeographicLib.

Click on one of the 9 areas to down load the data and a map of that area of the world. A new map of that area of the world will be displayed. Once in an area of the world many points can be processed. Move the pointer over the map. The latitude and longitude are displayed as it moves.

GeoidGE is a graphical front end for the NGS online tool, GEOID12B, that eliminates the need to input geodetic coordinates and displays the converted height, geoid separation, and scale factor in a placemark balloon. Both ellipsoid-to-orthometric and orthometric-to-ellipsoid height conversions are supported.