The accuracy of future space-based astrometric observations is expected to attain a level of 1 microarcsecond. In this paper, the authors briefly describe a relativistic model of space-based optical positional observations valid at a high level of accuracy, and suggest definitions of parallax, proper motion, and radial velocity compatible with general relativity at a level of 1 microarcsecond. Although the definitions are quite simple (see Klioner and Kopeikin, 1992), their ...
Reports by Author
