Investigation of subdaily and episodic variations of Earth rotation observed by VLBI, ring laser gyroscopes and GNSS

01.08.2009 - 31.07.2012
Research funding project
The primary objectives of project SPEED are to determine high-quality Earth rotation parameter (ERP) series with a time resolution of one hour or less derived from various modern space geodetic techniques, namely GNSS (GPS, GLONASS, ...), Very Long Baseline Interferometry (VLBI), and ring laser gyroscopes, and to provide a concise interpretation of these series. Polar displacement associated with earthquakes, the effect of episodic atmospheric disturbances (storms, tornados, cyclones) and of tsunamis are a main focus of the research. After removing all periodic signals for which a refined empirical model will be developed, the investigation of the above-mentioned non-tidal events has a bigger chance of success. This also requests a detailed modeling of atmospheric and oceanic excitation based on geophysical data in the high-frequency range. In the next phase of the project a Kalman filter will be developed for combining VLBI and GNSS with the Wettzell ¿G¿ ring laser observations. For the Wettzell gyroscope the sub-daily signatures of the relative Sagnac frequency should be understood to the sub-milliarcsecond level. Special emphasis will be given to the effects of the tri-axiality of the Earth and its consequences for the rotational behaviour of the Earth. An in-depth study of the Nearly Diurnal Free Wobble (NDFW) characteristics from VLBI-derived hourly polar motion will complete the investigations.

People

Project leader

Project personnel

Institute

Grant funds

  • Deutsche Forschungsgemeinschaft e.V (EU) German Research Foundation (DFG)

Research focus

  • Beyond TUW-research focus: 20%
  • Sustainable and Low Emission Mobility: 30%
  • Environmental Monitoring and Climate Adaptation: 50%

Keywords

GermanEnglish
Erdrotation Earth Rotation
geodätische Raumtechnikenspace geodetic techniques
atmosph. + ozeanische Drehmomenteatmpspheric+oceanic induced AM

Publications