In the equation h = H + N, what does N represent?

In the equation h = H + N, the symbol N represents the ellipsoid-geoid separation, also known as the geoidal height. This is critical in geodesy as it is the difference between the height of the ellipsoid (a mathematical model of the Earth's shape) and the geoid (a model of Earth's mean sea level) at a specific location.

To break it down further, h represents the height above the ellipsoid (ellipsoidal height), and H represents the height above the geoid (geoidal height). Therefore, N as the ellipsoid-geoid separation serves as a conversion factor that allows the transition between the two different height systems. By adding this separation to the height above the geoid, we can determine height above the ellipsoid. Understanding this relationship is vital for geodetic measurements and applications, as it helps in accurately positioning and mapping in the three-dimensional space of the Earth's surface.