At 07:32 PM 11/13/2002 -0500, you wrote:

>I _have_ heard of software that does a decent job of tracking by
>sending directional slew commands ("set the following guiding/slew
>rate... move left... move up... stop..."), all timed so that the overall
>motion will be passably close to that of the target object. Dunno how
>well this works, and don't remember any details. Anybody know
>what I'm talking about?

Yes. I have quite a bit of experience with this sort of thing.

Basically, I've yet to see a mounting that is accurate enough to pull this
off well and consistently using dead reckoning positioning commands. It is
possible that SciTech mountings are good enough; these appear to be a cut
above the average and their performance in other aspects is up to the
required spec, but I've not actually tried it.

The best method that I am aware of is to auto-guide on a star, making
incremental adjustments to the autoguider's target position in such a way
as to track the moving object. Alternately, for those with separate guiding
optical systems, guiding on the object of interest directly.



--
Jeff Medkeff
Sierra Vista, Arizona
http://www.roboticobservatory.com/jeff/