Modern Computer Control for Lick Observatory Telescopes

摘要

Poco, short for Pointing Control, is a modern telescope control system for use with the telescopes at Lick Observatory. It is currently in use with the Shane 3-meter and Nickel 1-meter telescopes. It may also be used with other telescopes in the future. The software is designed to be very reliable, accurate, flexible, and full featured while still being very easy to use. It needs to communicate with other systems such as auto-guiders, instruments, remote observing watchdogs, and possible robotic control. The telescopes use motor systems installed in the 1970's. Upgrading to modern servo motors was not practical, so the telescopes use their stepper motors for fine motor control while switching to much larger and less accurate motors for large moves. It requires a variety of techniques to quickly and smoothly reach target locations and maintain tracking. The software achieves these goals, overcoming the significant hardware limitations of these older telescope using mostly off the shelf hardware. This paper will describe the more interesting aspects of the system such as locating objects from catalog coordinates, motor control algorithms, user interfaces, communications between systems, and software architecture.