Automatic Horizontal Meridian Circle at Pulkovo

The goal of the new design and modernization of transit circles is complete automation (Pinigin and Shornikov,1983; Hughes,1982; Requieme and Mazurier,1982). For example, all the essential steps of star observations and the determination of the instrument parameters have been automatized at the Tokyo and Brorfelde Observatories (Yoshizawa and Yasuda, 1982; Fogh Olsen and Helmer, 1978). Computer control was introduced for the automation of all the major operations of the Pulkovo horizontal meridian circle (HMC). This involves an automatic setting system (mirror setting), a circle reading system, two photoelectric eyepiece micro-meters, meteorological data sensors and a rotating drive of the pendulum horizon (Figure 1). All these are controlled by a microcomputer of the “Electronica C5-12” type.