Automatic precise alignment of the hour axis
The movement of the planets or distant star systems is described by means of the celestial mechanics. The star trails on a celestial photograph do not obey these laws but the star trails are to a large extent computable and are governed by the laws of refraction, dispersion and in most cases by pure geometry due to the position of the hour axis. There are several methods, how the position of the hour axis can be measured and then moved to the celestial pole or better to the apparent pole by “human intervention”.
With the nowadays available computers or hand controllers it is really a matter of doing it to implement the different methods of the measurements. The calculations are by no means demanding what cpu power concerns. Even the correct drive rate of a equatorially mounted telescope is more or less a simple formula. Further the steering of the motors, which move the hour axis in azimuth and elevation is a task which can be accomplished within weeks.
An automatic precision alignment of the hour axis needs the following existing components:
a web-, video- oder CCD camera
two motors to move the hour axis in azimuth and elevation
a computer (e.g. hand controller)
The procedure is completely analogous to the manually performed alignment. The motors need a higher torque than the motors used for tracking. The number of revolutions per unit angle can be measured at first or if the correction angle is small directly monitored on the screen of the CCD camera.
Each of these tasks is already solved in this or another form and the costs and the hours to realize such a prototype should be counted in days rather than in months.