5. Summary

The information in this chapter barely scratches the surface of gravity measurement. Gravity determination and geoid modeling are part of physical geodesy, a specialty within the geodetic science. Horizontal and vertical (and in the future, 3D) datums are dependent on the geoid. Because the Earth is not a static figure, gravity needs to be continually monitored to obtain the best geoid model representation. Better models are needed as technology continues to allow higher levels of measurement accuracy. What we couldn't discern 20 years ago has become routine today and will be considered crude tomorrow.