Basic principles of scanning space astrometry

L. Lindegren; U. Bastian

doi:10.1051/eas/1045018

All issues

Volume 45 (2010)

EAS Publications Series, 45 (2010) 109-114

Abstract

Issue		EAS Publications Series Volume 45, 2010 GAIA: At the Frontiers of Astrometry


Page(s)		109 - 114
DOI		https://doi.org/10.1051/eas/1045018
Published online		15 February 2011

GAIA: At the Frontiers of Astrometry
C. Turon, F. Meynadier and F. Arenou (eds)
EAS Publications Series, 45 (2010) 109-114

Basic principles of scanning space astrometry

L. Lindegren¹ and U. Bastian²

¹ Lund Observatory, Lund University, Box 43, 22100 Lund, Sweden
² Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12–14, 69120 Heidelberg, Germany

Abstract

We outline the basic principles of scanning space astrometry, such as represented by Hipparcos, Gaia, and some other astrometric satellites planned or proposed. We explain the need for large-angle measurements, why these are essentially one-dimensional, how it is possible to determine absolute parallaxes, and why a Hipparcos-type scanning law is favourable. We discuss the choice of the basic angle between the two viewing directions, the principle of self-calibration, and why the resulting numerical problem must be difficult to solve.