Land Surveyor Forum

Replies

• Land Surveyor

  J. Anthony Cavell October 23, 2018 at 12:27pm

  Dear Mr. Chams,

  It is impossible to answer your question with particular certainty. In order to do so, one needs to know the location of your survey, the desired datum to which you wish to refer the height. It may further require knowing the appropriate geoid model.

  WGS84 coordinates are 3-D. They may be expressed as X, Y, Z Cartesian coordinated from the center of mass of Earth or as Latitude, Longitude, and Ellipsoid Height. If it is elevation (orthometric height) you wish, then one must subtract the geoid height from the ellipsoid height to approximate the orthometric height (elevation).

  That assumes you have proper 3-D WGS84 coordinates. Perhaps your horizontal position is good but the ellipsoid height is poor. In that case, the direct solution is to find a reliable benchmark and level from there to your points of interest.

  JAC
  • Land Surveyor

    khaldoun azzazi > J. Anthony Cavell October 23, 2018 at 4:06pm

    yes anthony you are right