The NDAC HIPPARCOS data analysis consortium - Overview of the reduction methods
Snijders, M. A. J.; Evans, D. W.; Lindegren, L.; van Leeuwen, F.; Perryman, M. A. C.; Petersen, C.; Hog, E.; Ramamani, N.; Murray, C. A.; Penston, M. J.
Sweden, Denmark, United Kingdom, Netherlands
Abstract
This paper gives an overview of the assumptions and algorithms adopted by the Northern Data Analysis Consortium (NDAC) for the reduction of data from the space astrometry satellite Hipparcos. A fairly detailed account is given of the main steps of the reduction, viz., the attitude determination, analysis of image dissector tube data, great-circle reductions and sphere solution. Of these, only aspects of the attitude determination have required substantial revision due to the satellite's failure to reach geostationary orbit. A brief outline is given of the instrument calibrations and the analysis of non-single stars.