What do the terms geoid, ellipsoid, spheroid and datum mean, and how are they related?
The {BOLD}geoid{/BOLD} is defined as the surface of the earth’s gravity field, which is approximately the same as mean sea level. It is perpendicular to the direction of gravity pull. Since the mass of the Earth is not uniform at all points, and t… • Geographic Coordinate Systems by Area of Use 8.x; 9.0; 9.1 • Geographic Coordinate Systems by Area of Use 9.2 • Geographic Coordinate Systems and Area of Use 9.