Posted By Tom Licha
I permanently installed GEM last year.
Firest I used the polar alignment scope. Then I changed to CCD exposures. I increased focal length wit a 3x barlow lens. This brings out any tracking errors mor easy.
I took pictures starting from 1 min. to longer and longer. In between I corrected the alignment. I did it with trial and error. 50% chance to get the direction right is OK. Then keep this direction until there is no further improvement...
BTW: By doing it with real CCD exposures you are also correcting for the error of refraction in the atmosphere. Hence this method is even better than theoretically perfect north pole alignment.
The procedure took me one whole night, but I did not have to touch it since 15 months. My rest error over appr. 1 hour is only periodic error of worms.
http://www.licha.de/AstroWeb 49° 13' 54" N