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Sample Batch Files Available

If you need help with the “Batch Processing” file format for CSV files you can now download sample files by clicking on the "Help for GPSH" link below.

Geoid velocity added

To correct for the vertical drift between reference frames, the velocity of the geoid height (VN) is now calculated and incorporated into the calculation of the orthometric height. View the GPS·H update documentation to learn more.

Help for GPS·H

GPS·H allows the conversion of GNSS ellipsoidal heights h — either in NAD83(CSRS) or ITRF — to orthometric heights H (heights above mean sea level) through the application of a gravimetric or hybrid geoid model. The application allows also the reversed conversion (H to h), and the conversion between two vertical datums Ha to Hb) (e.g., CGVD28(HT2_0) to CGVD2013(CGG2013a)). When applying the Canadian Gravimetric Geoid model CGG2013a, the orthometric heights are directly integrated into the Canadian Geodetic Vertical Datum of 2013 (CGVD2013). On the other hand, the Height Transformation v.2.0 (HTv2.0) provides heights compatible with the Canadian Geodetic vertical Datum of 1928 (CGVD28) when the ellipsoidal heights are at epoch 1997.0. GPS·H includes HTv2.0 models for each of the adopted NAD83(CSRS) epochs (1997.0, 2002.0, 2010.0). The other geoid models do not convert to either CGVD2013 or CGVD28, but to their own reference system.

GPS·H now calculates the velocity of the geoid height, displayed as a separate value, and is incorporated into the calculation of the orthometric height.

The online version accepts the following types of input coordinates: geographic, Cartesian, and UTM/MTM/Stereographic/Lambert conformal conic. By clicking the "Batch Processing" box, you can submit coordinates in a file. The "Input H" box is for the reversed conversion (H to h).

Batch Processing


Single Calculation



h (metres)
H (metres)
N (metres)
Gravity (mGal)
Hd (metres)
VN (mm/year)
H28 (metres)
dH (metres)
H2013 (metres)
H2013 (metres)
dH (metres)
H28 (metres)

Use of Canadian Geodetic Survey products and data is subject to the Open Government Licence - Canada

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