(1) Observatoire de Bordeaux, URA 352 CNRS, BP 89, 33270 Floirac (France)
(2) IAG-USP, Departamento de Astronomia, CP 9638, 01065, Sao Paulo (Brazil)
(3) Copenhagen University Observatory, Juliane Maries Vej 30, DK 2100 Copenhagen OE
(4) Copenhagen University Observatory, Oestervoldgade 3, DK 1350 Copenhagen
A first CCD camera working in 'scan' mode has been tested during 9 months on the Bordeaux automatic meridian circle, then mounted on the Sao Paulo meridian instrument. A second improved camera, with a larger field (28'), was installed at Bordeaux last April.
Using as reference preliminary positions of the Tycho stars, kindly provided by the Tycho Consortium for 11 fields, and the corresponding proper motions obtained by S.Roeser from a preliminary reduction of the Astrographic Catalogue and the Guide Star Catalogue, the accuracy of our positions (obtained with our first camera) was found to be about 0.05'' up to V=15, for a star measured at least 4 times in the declination range -16 to +62 degrees.
Comparisons with results of the CCD meridian instruments of Sao Paulo and Flagstaff (USNO), on common fields, give a similar estimate for the Bordeaux accuracy. This accuracy was also confirmed (at least up to V=14.3) by a series of 13 observations of Pluto obtained in 1995 and compared to the new J.P.L. ephemerides DE403.