GPS·H allows the conversion of ellipsoidal heights h, that are
either NAD83 (CSRS) or ITRF, to orthometric heights H (heights
above mean sea level) by using a gravimetric or hybrid geoid model.
CGG2013 and HTv2_0 convert to CGVD2013 and CGVD28, respectively. The
other geoid models do not convert to either CGVD2013 or CGVD28, but to
their own reference system.
The on-line version accepts the following types of input coordinates:
geographic, Cartesian and UTM/MTM/Stereographic. 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).