ResearchResearch Projects
Lunar Laser Ranging: Konsistente Modellierung für geodätische und wissenschaftliche Anwendungen

Lunar Laser Ranging: Konsistente Modellierung für geodätische und wissenschaftliche Anwendungen

Leaders:  Prof. Dr.-Ing. Jürgen Müller
Email:  mueller@ife.uni-hannover.de
Team:  Dr.-Ing. Liliane Biskupek
Year:  2006
Sponsors:  DFG
Is Finished:  yes
More Link https://www.erdrotation.de/

Within the DFG research group "Earth rotation and global dynamic processes" the subproject Lunar Laser Ranging: Consistent Modelling for geodetic and scientific applications is working on the improvement and extension of the existing models of the evaluation software for laser measurements to the Moon (LLR).

The evaluation of LLR data is possible with the software package currently available at the Institute for Geodesy in an accuracy range of 1-2 cm. In addition to the determination of many parameters in the Earth-Moon system (e.g. station and reflector coordinates, moon orbit parameters), investigations in the field of Earth rotation can also be carried out (e.g. long-periodic nutation coefficients, pole movement and precession constant). By increasing the accuracy, the results can be better compared with the results of other geodetic space methods (e.g. VLBI - Very long baseline interferometry).

To achieve this goal, the existing evaluation models described the components for Earth rotation according to the IERS Conventions 2010. The estimate of the long-period lunisolar nutation coefficients was extended so that not only the coefficients of the 18.6-year period but also those of the 9.3-year, 1-year and 182.6-day periods can be determined. Also, the estimation of Earth rotation parameters (ERP) has been changed. Previously, the parameters of the Earth-Moon system, without ERPs, were estimated from the LLR data in an adjustment. From the resulting residuals, the Earth rotation quantities were determined using the daily decomposition method. Possible correlations between parameters of the Earth-Moon system and the ERPs could not be determined in this way. To enable the direct estimation of the Earth rotation quantities, the global adjustment was extended and now allows the determination of the polar coordinates xP and yP together with the Earth-Moon parameters for relevant time periods.