SLR data analysis

DGFI contributes to the activites of Analysis Working Group of the International Laser Ranging Services (ILRS-AWG) as analysis centre. This includes the regular submission of coordinates and earth orientation parameters from satellite ranging (SLR) observations to the geodetic satellites Lageos1/2 und Etalon1/2. These results were, together with the results from the 8 other analysis centres, combined to the official ILRS product by 2 combination centres. The membership in the ILRS-AWG also requires the reprocessing of all SLR data from Lageos and Etalon back to 1983 for international projects like ITRF2008.

As member of the ILRS-AWG DGFI has undertaken the task of monitoring active SLR stations in terms of accuracy and reliability, and for new stations or stations which had a longer maintenance break validate the data delivered. For this purpose, a daily bias report is prepared and published on the Internet. Unusual values of range or time biases were reported promptly to the stations for correction to assure the quality of the tracking network.

In addition, separately from the ILRS AWG own calculations using the SLR data, such as the provision of low harmonic coefficients of Earth's gravity field, see figure, or studies on effects of different models on the orbit determination and derived parameters. In addition other satellites are be used for new calculations and model approaches, such as low degree harmonics. Participation in future projects as part of GGOS is provided.

: Comparison of low degree harmonics computed at DGFI with a solution from CSR, Texas.

Selected publications

Bloßfeld M., Müller H., Seitz M., Angermann D.: Benefits of SLR in epoch reference frames. Proceedings of the 17th ILRS Workshop, 2011

Bloßfeld M., Müller H., Angermann D.: Adjustment of EOP and gravity field parameters from SLR observations Proceedings of the 17th ILRS Workshop, 2011

Mueller H.: Statistical Analysis in 20xx. Proceedings of the 17th ILRS Workshop, 2011

Müller H., Angermann D.: The InternationalTerrestrial Reference Frame - Latest Developments. Proceedings of the 16th International Workshop on Laser Ranging, Poznan, Poland,Vol.1, 27-34, 2009

Angermann D., Müller H.: On the strength of SLR observations to realize the scale and origin of the terrestrial reference system. In: Sideris, M.G. (Ed.): Observing our Changing Earth, IAG Symposia, Vol. 133, 21-27, 2009

Kelm R.: Rigorous variance component estimation in weekly intra-technique and inter-technique combination for global rerrestrial reference frames. Springer, IAG Symposia, Vol. 134, 39-44, doi: 10.1007/978-3-642-00860-3_6, 2009, 2009

Müller H., Angermann D.: Some Aspects Concerning the SLR Part of ITRF2005. In: Luck J., Moore Ch., Wilson P. (Hrsg.): Proceedings of the 15th International Workshop on Laser Ranging, EOS Space Systems PTY Limited, Canberra, 2008

Müller H.: Analysis of Multi-Wavelength SLR Tracking Using Precise Orbits. In: Luck J., Moore Ch., Wilson P. (Hrsg.): Proceedings of the 15th International Workshop on Laser Ranging, EOS Space Systems PTY Limited, Canberra, 2008