FOR 1503:  Space-Time Reference Systems for Monitoring Global Change and for Precise Navigation in Space

• Subject Area: Geosciences ; Physics
• Term: from 2011 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 165956021

The concepts of reference systems are as old as the first geometric considerations of the shape of bodies in general and of the Earth in particular. Reference systems are, thus, an indispensable component for the description of the geometry and the kinematics of the Earth and other objects in space. Since the determination of geometrical properties of these objects has gained more and more relevance, the issues of the appropriate reference systems became even more important. Today, accurate form parameters of space objects are of interest while for the Earth monitoring and quantifying Global Change are in the focus of scientific investigations.
The main objective of the Research Unit is to develop integrative methods and procedures for a consistent definition and realisation of reference systems on Earth and in space. Although many realisations of reference systems exist already, they are used independently and suffer from inconsistencies. In an environment of ever increasing observing capabilities as well as of social and scientific needs, a framework of reference systems will be produced, which are linked consistently with an appropriate level of accuracy to guarantee a solid basis for measuring geometric effects of Global Change and for high-precision navigation near Earth and in deep space.
The contributions of various groups active in geodetic, astronomical and space sciences will enable a comprehensive interdisciplinary treatment of reference systems. In order to concatenate the existing astronomical and geodetic observing material into a consistent framework, it is necessary to improve the theoretical foundations and the practical processes for the realisation.
In six projects, barycentric ephemerides, moon-related systems and satellite-based dynamic reference systems as well as Earth-based systems will be developed further and brought together consistently. Models have to be improved for the combination of the observations of different space-geodetic observations like Very Long Baseline Interferometry, precise GPS, Satellite Laser Ranging and Lunar Laser Ranging with millimetre accuracy. As a final result, a consistent set of reference systems for the Earth, artificial satellites, the Moon, selected planets and for the far-distant compact radio galaxies will be realised with unprecedented accuracy.

• DFG Programme: Research Units
• International Connection: Switzerland

Projects

• Barycentric Ephemeris (Applicants Müller, Jürgen ;  Oberst, Jürgen )
• Co-location of Space Geodetic Techniques on Ground and in Space (Applicants Rothacher, Markus ;  Schreiber, Ulrich )
• Consistent celestial and terrestrial reference frames by improved modelling and combination (Applicants Angermann, Detlef ;  Thaller, Daniela )
• Consistent dynamic satellite reference frames and terres-trial geodetic datum parameters (Applicants Hugentobler, Urs ;  Seitz, Manuela )
• International Celestial Reference Frame (ICRF-3) (Applicant Nothnagel, Axel )
• Lunar Reference Systems (Applicants Kusche, Jürgen ;  Müller, Jürgen ;  Oberst, Jürgen )
• Space-Time Reference Systems for Monitoring Global Change and for Precise Navigation in Space (Applicant Nothnagel, Axel )
• Ties between kinematic and dynamic reference frames (D-VLBI) (Applicant Schuh, Harald )

• Partner Organisation: Fonds zur Förderung der wissenschaftlichen Forschung (FWF); Schweizerischer Nationalfonds (SNF)
• Spokesperson: Privatdozent Dr.-Ing. Axel Nothnagel