Global Terrestrial Reference Frames

[Realization of the ITRS at DGFI-TUM]

The International Terrestrial Reference System (ITRS) is the fundamental terrestrial reference system and serves as basis for describing the figure of the Earth and for referencing processes at the Earth's surface, in the Earth's immediate space environment and in the Earth's interior. The ITRS is realized by positions and velocities of more than 1700 globally distributed geodetic observing stations. Station positions and velocities are derived from a combination of the space geodetic techniques Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Satellite Navigation Systems (GNSS, e.g., GPS and GLONASS), and the Doppler measurement system DORIS (see Figure). Each of the techniques provides individual strengths with respect to the determination of geodetic parameters - in particular the parameters of the geodetic datum (origin, orientation, and scale of the reference frame). A combination of the different techniques allows for exploiting their potentials in an optimal way.

The computation of the reference frame is performed as shown in the flowchart. In a first step, the time series of normal equation systems of the individual techniques are analyzed and combined to one normal equation system per technique (intra-technique combination). In a second step, the normal equation systems of the different techniques are combined (inter-technique combination).

In its role as an "ITRS Combination Centre" within the International Earth Rotation and Reference Systems Service (IERS), DGFI-TUM took the responsibility for the continuous realization of the ITRS with the best possible accuracy and long-term stability. DGFI-TUM's latest realization of the ITRS is the DTRF2014.

The major goal of DGFI-TUM's research activities in this context is to further develop the global reference frame by improving its accuracy, stability, actuality, and consistency. In particular DGFI-TUM investigates the potential and optimal strategy for the consistent realization of the terrestrial and celestial reference system according to Resolution 3 (2011) of the International Union of Geodesy and Geophysics (IUGG), and the integration of geometry and gravity in the sense of GGOS.

Related project

Selected Publications

Seitz M., Bloßfeld M., Angermann D., Schmid R., Gerstl M., Seitz F.: The new DGFI-TUM realization of the ITRS: DTRF2014 (data). Deutsches Geodätisches Forschungsinstitut, Munich, 10.1594/PANGAEA.864046, 2016 (Open Access)
Seitz M., Angermann D., Bloßfeld M.: Geometrische Referenzsysteme. In: Freeden W., Rummel R. (Eds.), Handbuch der Geodäsie, 10.1007/978-3-662-46900-2_17-1, 2016
Seitz M., Angermann D., Gerstl M., Bloßfeld M., Sánchez L., Seitz F.: Geometrical Reference Systems. In: Freeden W., Nashed M.Z., Sonar T. (Eds.) Handbook of Geomathematics (Second Edition), Springer, pp 2995-3034, 2995-3034, 10.1007/978-3-642-54551-1_79, 2015
Bloßfeld M., Seitz M., Angermann D., Moreaux G.: Quality assessment of IDS contribution to ITRF2014 performed by DGFI-TUM. Advances in Space Research, 58(12), 2505-2519, 10.1016/j.asr.2015.12.016, 2016
Seitz M., Angermann D., Bloßfeld M., Gerstl M., Müller H.: ITRS Combination Centres: Deutsches Geodätisches Forschungsinstitut (DGFI). In: Dick W.R., Thaller D. (Eds.) IERS Annual Report 2014, Verlag des Bundesamts für Kartographie und Geodäsie, pp 120-123, 2015
Seitz M., Steigenberger P., Artz T.: Consistent adjustment of combined terrestrial and celestial reference frames. In: Rizos C., Willis P. (Eds.) Earth on the Edge: Science for a Sustainable Planet, IAG Symposia 139: 215-221, Springer, 10.1007/978-3-642-37222-3_28, 2014
Angermann D., Seitz M., Drewes H.: Global terrestrial reference systems and their realizations. In: Xu G. (Ed.) Sciences of Geodesy II - Innovations and Future Developments, 97-132, Springer, 10.1007/978-3-642-28000-9_3, 2013
Seitz M., Angermann D., Bloßfeld M., Drewes H., Gerstl M.: The 2008 DGFI realization of the ITRS: DTRF2008. Journal of Geodesy, 86(12), 1097-1123, 10.1007/s00190-012-0567-2, 2012
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, 10.1007/978-3-540-85426-5_3, 2009
Drewes H.: Reference systems, reference frames, and the geodetic datum - basic considerations. In: Sideris, M.G. (Ed.): Observing our Changing Earth, IAG Symposia 133: 3-9, Springer, 10.1007/978-3-540-85426-5_1, 2009

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