A Practical Relativistic Model for Microarcsecond Astrometry in Space

By S. Klioner. 2001

150 citations recorded by the source corpus.

We develop a practical model for relativistic reduction of positional observations with an accuracy of 1 μas, which is expected to be attained in future space astrometry missions. All relativistic effects that are caused by the gravitational field of the solar system and are of practical importance for this accuracy level are thoroughly calculated and discussed. The model includes relativistic modeling of the motion of the observer and modeling of relativistic aberration and gravitational light deflection, as well as a relativistic treatment of parallax and proper motion suitable for the accuracy of 1 μas. The model is formulated both for remote sources (stars, quasars, etc.) and for solar system objects (asteroids, etc.). The suggested model is formulated within the framework of the parameterized post-Newtonian formalism, with parameters β and γ. However, for general relativity (β = γ = 1) the model is fully compatible with the year 2000 IAU resolutions on relativity in celestial mechanics, astrometry, and metrology. The model is presented in a form suitable for implementation in a software system for data processing or simulation. The changes that should be applied to the model to attain an accuracy of 0.1 μas are reviewed. Potentially important relativistic effects caused by additional gravitational fields that are generated outside of the solar system are also briefly discussed.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/7def16659743738f89ac87b4d6e73a48bd91ea60

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Citations in the corpus

The fundamental definition of "radial velocity'' (2003, background): “…within a general-relativistic framework has been treated in textbooks such as Murray (1983), Soffel (1989) and Brumberg (1991), and various aspects of it have been dealt with in several papers (e.g. Stumpff 1985; Backer & Hellings 1986; Klioner & Kopeikin 1992; Klioner 2000b; Klioner 2003).”
Barycentric Corrections at 1 cm s-1 for Precise Doppler Velocities (2014, unknown): “We represent the total magnitude of proper motion by µ (in units of radians yr−1, see Wright & Howard (2009), or the Astronomical Almanac; there are also light-deflection and other corrections that must be made for precise astrometry, but they are not important at the 1 cm/s level (Klioner 2003)).”
Gaia Data Release 2 (2018, methodology): “Relevant components of the model are gathered in the Gaia relativity model (GREM; Klioner 2003, 2004).”
The IAU 2000 Resolutions for Astrometry, Celestial Mechanics, and Metrology in the Relativistic Framework: Explanatory Supplement (2003, background): “Work in this direction has already started (Klioner 2003).”
Gaia Early Data Release 3 (2020, methodology): “The Gaia relativity model (Klioner 2003, 2004) provides a rigorous generalrelativistic modelling of astrometric observations.”