Use of Gravity Measurements in Defining and Realizing Reference Systems for Geodynamics

Abstract

Single measurements of gravity cannot give sufficient information about the position of measuring points with respect to some terrestrial reference system. Only a set of gravimetric stations all over the Earth combined with a determination of their coordinates allows one to determine (from the solution of Molodensky’s problem) the heights of these stations with respect to a level ellipsoid with center at the geocenter. Given in addition their heights above some reference ellipsoid, whose position in the Earth’s body is fixed through a set of reference points on its surface, the position of the geocenter in the same reference system may be obtainedo

Wider opportunities are opened through repeated gravity measurements. They are bound up with the fact that an essential part of nontidal variations of gravity is caused by the height variations of gravity stations. In this report the relation between gravity and height variations is considered, taking into account the latest results of gravity variation investigations.