From the Roemer mission to Gaia

E. Høg
2007 Proceedings of the International Astronomical Union  
AbstractAt the IAU symposium in Shanghai September 1992 the present author made the first proposal for a specific mission concept post-Hipparcos, the first scanning astrometry mission with CCDs in time-delayed integration mode (TDI). Direct imaging on CCDs in long-focus telescopes was described as later adopted for the Gaia mission. The mission called Roemer was designed to provide accurate astrometry and multi-colour photometry of 400 million stars brighter than 18 mag in a five-year mission.
more » ... he early years of this mission concept are reviewed.
doi:10.1017/s1743921308019418 fatcat:2jzkksgczbe4jkl645ybu7xy3a