Relativistic Geodesy

Meanwhile the precision of clocks, particularly of optical clocks, is so high that a rate difference of clocks based on changes of the gravitational potential can be measured with a height variation of just a few centimeters. Therefore, optical clocks can be used to determine the gravitational potential. They also provide a new observation parameter for heights, make the overcoming of great distances possible and thus the connection of far-away areas to height systems.

Relativistic geodesy can also be applied in space. The mass of Sun, Moon and Earth provide through the analysis of distance measurements to the moon extraordinary opportunities for testing Einstein's theory of relativity.