Combined analysis and validation of Earth rotation models and observations (CAVERMO)

Within the project CAVERMO an integral analysis of the geometric and gravimetric observations from space geodetic techniques is performed to evaluate accurate and consistent time series of the Earth rotation parameters (ERP), the low-degree spherical harmonic coefficients of the Earth’s gravitational potential as well as the integral geophysical excitation functions. The figure below shows the project structure.

: Flowchart of the project: The project part of DGFI is shown on the right-hand side; at the bottom means the part of TUM, at the left the part of project partners at the University of Hannover is shown. Within the DGFI part time series of excitation functions from different Earth system components are determined from the observations of space geodetic techniques.

At DGFI individual geophysical excitation mechanisms of the Earth rotation are determined from space-geodetic observation techniques. Until now the individual contributions of the subsystems of the Earth could be only estimated from geophysical models. Due to the combination of different space-geodetic observations in terms of Earth rotation, gravity field and sea level changes the atmospheric, oceanic and hydrological mass effects can be determined as well as the integral motion effect. We assume that the combined geodetic results are more realistic than the geophysical model solutions because they are based on precise space-geodetic measurements.

Project information

Funding: DFG-Research Group Earth Rotation (DFG-FOR 584)

Period: 04/2009 - 05/2012

Project partners: TU Munich (IAPG), Leibniz University Hannover (GIH)

Responsible persons at DGFI: Michael Schmidt, Franziska Göttl

Selected publications

Göttl F.: Earth rotation variations from geometric, gravimetric and altimetric observations and geophysical models. DGFI Report 84, Deutsches Geodätisches Forschungsinstitut (DGFI), München, 2008

Göttl F., Seitz F.: Contribution of non-tidal oceanic mass variations to polar motion determined from space geodesy and ocean data. in: Sideris, M.G. (eds.) Observing our Changing Earth, IAG Symposia, Vol. 133, pp 439-445, Springer, ISBN (Print) 978-3-540-85425-8, ISBN (Online) 978-3-540-85426-5, ISSN 0939-9585, DOI: 10.1007/978-3-540-85426-5_53, 2008

Mladek F. (2006): Hydrostatische Isostasie, Schriftreihe IAPG/FESG No.24, Institut für Astronomische und Physikalische Geodäsie, München

Schmidt M., Angermann D., Bloßfeld M., Göttl F., Richter B., Seitz M.: Erdrotation und geophysikalische Anregungsmechanismen. Zeitschrift für Vermessungswesen, 135, Heft 2, 2010