Online geoid calculations using the GeoidEval utility

Position (ex. «16.78 -3.01», «16d46'33"N 3d0.6'W»):
   

Select action:
   

Geoid height:

    lat lon =  
    geoid heights (m)
	EGM2008 = 
	EGM96   = 
	EGM84   = 


GeoidEval computes the height of the geoid above the WGS84 ellipsoid using interpolation in a grid of values for the earth gravity models, EGM84, or EGM96, EGM2008. The RMS error in the interpolated height is about 1 mm. Give the position in terms of latitude and longitude, for example (these all refer to the position of Timbuktu):

        16.776 -3.009
        16d47' -3d1'
        W3°0'34" N16°46'33"
        3:0:34W 16:46:33N
The coordinates can also be given in UTM, UPS, or MGRS coordinates (see the documentation on the GeoConvert utility).

The geoid height, N, can be used to convert a height above the ellipsoid, h, to the corresponding height above the geoid (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. This web interface illustrates a subset of its capabilities. If you wish to use GeoidEval directly, download and compile GeographicLib. A description of the methods is given here.


Charles Karney <charles@karney.com> (2014-11-06)
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