Toggle Main Menu Toggle Search

Open Access padlockePrints

Toward an improved orthometric height system for Canada

Lookup NU author(s): Dr Robert Tenzer


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Heights in Canada are defined in the system of orthometric heights, according to a method proposed by Helmert in 1890. However, much development in the theory of heights has been done since then, leading to a more rigorous definition of orthometric heights. The new definition takes into account the effects of terrain roughness, laterally varying anomalous topographical density, and the NT geoid-generated gravity disturbance, which are not considered in the Helmert method. This paper presents a calculation of corrections to Helmert orthometric heights, to update them to the more rigorous definition. The corrections for each effect, as well as a total correction comprising all three effects, are evaluated for a Canadian test area which includes several types of terrain. The correction is found to reach decimetres in some mountainous areas.

Publication metadata

Author(s): Kingdon R, Vanicek P, Santos M, Ellmann A, Tenzer R

Publication type: Article

Publication status: Published

Journal: Geomatica

Year: 2005

Volume: 59

Issue: 3

Pages: 241-249

Print publication date: 01/01/2005

ISSN (print): 1195-1036

ISSN (electronic):

Publisher: Canadian Institute of Geomatics