The Astrometry Division

The Astrometry Division, the former group for time and latitude determination which was set up in 1973, was founded in 1977. Altogether the Division has twenty scientific and technician workers, with 4 quartz clocks, 3 rubidium clocks,a pliotoelcctric aslrolabc and a plioloclectric transit instrument;and ihereforc there are three study groups,i.e., the clock room group, the astrolabe group and the transit instrument group,under the Division. The work such as the time keeping, the determination of time and latitudes,the experiments made with the meridian cycle at middle and lower latitudes, has deeh done successively. The first two pieces of work have provided data for the utiiversal time service in China, and the last has obtained the result that the absolute azimuth error of a single star is determined to be ±13.4 ms by observing at the prime vertical and therefore the feasibility of this method has been verified.