Geoid Height Calculator

Enter latitude, longitude, and GPS height and then submit:


degrees North
minutes North
seconds North

E.g. enter the latitude as –56.25 degrees or –56 degrees 15 minutes, for 56 degrees 15 minutes South.


degrees East
minutes East
seconds East

E.g. enter the longitude as –102.5 degrees or –102 degrees 30 minutes, for 102 degrees 30 minutes West.

GPS Elevation: meters

[Note: For multiple point entry, use comma-delimited lists in the entry boxes, but make sure that each entry box used has the same number of comma-delimited entry values.]

Specific Information on the EGM96 Model and the Geoid Correction

This program is designed for the calculation of a geoid undulation at a point whose latitude and longitude is specified. The program is designed to use the potential coefficient model EGM96 and a set of spherical harmonic coefficients of a correction term.

The correction term is composed of several different components, the primary one being the conversion of a height anomaly to a geoid undulation. The principles of this procedure were initially described in the paper: Use of Potential Coefficient Models for Geoid Undulation Determination Using a Spherical Harmonic Representation of the Height Anomaly/Geoid Undulation Difference by R.H. Rapp, Journal of Geodesy, 1996.

This program is designed to be used with the constants of EGM96 and those of the WGS84(G873) System. The undulation will refer to the WGS84 ellipsoid.

Specific details of the undulation computation will be found in the joint project report describing the development of EGM96. This program is a modification of the program described in the following report: A Fortran Program for the Computation of Gravimetric Quantities from High Degree Spherical Harmonic Expansions, Richard H. Rapp, Report 334, Department of Geodetic Science and Surveying, The Ohio State University, Columbus, 1982. This program was put in this form in December 1996. RHRAPP.F477.NONLY

Comments or questions about this page? Send mail to Lou Estey.

Last modified Friday, 07-Jun-2013 17:42:18 UTC