Geoid – What is it? Why do we use it with Trimble TerraSync and GPS Pathfinder Office software?

Geoid - What is it? Why do we use it with Trimble TerraSync and GPS Pathfinder Office software? What is the Geoid?   The geoid is a model of global mean sea level that is used to measure precise surface elevations (definition according to NOAA). While we often think of the earth as a sphere, [...]