Enhanced G: Precision Ring Laser Earth Rotation Sensing for Space Geodesy at the Quantum Limit

• Antragsteller: Professor Dr.-Ing. Ulrich Schreiber
• Fachliche Zuordnung: Geodäsie, Photogrammetrie, Fernerkundung, Geoinformatik, Kartographie
• Förderung: Förderung von 2013 bis 2018
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 229768556

Continuous ring laser observations have successfully demonstrated to improve high frequency VLBI solutions in the combination process. This proposal aims at the improvement of the ring laser "G" by at least half an order of magnitude in sensitivity and more than one order of magnitude in stability with the goal to significantly contribute to the terrestrial reference frame. Over the last decade the stabilization of the ambient pressure and multiple feedback systems have improved G substantially. This made the detection of extremely slow processes like the Chandler wobble possible. A sensitivity of d-Omega/Omega of 5e-9 has been achieved repeatedly. Slow variations in the unavoidable backscatter coupling are the prominent remaining error source. In order to eliminate this effect it is intended to explore a regime, where the ring laser gyroscope runs on two different longitudinal laser modes. With the help of an optical frequency comb, a H-maser controlled Direct Digital Synthesizer and a broadband piezo feedback system, the required tight cavity control appears to be feasible. To make full use of these improvements, the existing geophysical models are to be combined into a comprehensive analysis package for gyroscopes used in geodesy.

• DFG-Verfahren: Sachbeihilfen