Abstract

Gyroscopes, i.e. rotation sensors, are nowadays installed in virtually every smartphone. The much more accurate ring lasers are used in aircraft and submarine navigation. In order to be able to use ring lasers for geophysical and geodetic purposes such as monitoring the Earth's rotation, their resolution and stability have been increased by several orders of magnitude. The large ring laser at the Geodetic Observatory in Wettzell is currently the only rotation sensor in the world capable of measuring changes in the length of the day of less than 1 millisecond. This enormous sensitivity also reveals local signals such as deformations caused by atmospheric or hydrological influences or seismic waves, from which additional rotational information about these processes can be obtained. The presentation describes the path from navigation instrument to Earth rotation sensor and presents the benefits of large ring lasers for geodesy and geophysics.