Hello,
I have been reviewing the basics of coordinate systems and trying to understand the role behind the Ellipsoid and Geoid. I understand that the height difference between the ellipsoid / geoid, and the height between earths topography / geoid are related (h=H+N). However, in my research I understand that a total station can be set to give elevation values on the Ellipsoid or the Geoid. So I have to ask: if the ellipsoid is an ideal shape of the earth with a simplified mathematical model, and I can work on the Ellipsoid grid to get my coordinates / elevations, why introduce the geoid at all?
