From: Milton Aupperle <milton@outcastsoft.com>

Date: February 15, 2008 9:16:46 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Polar Alignment etc...

Hi Folks;

Like Mark, I use a compass that is corrected for Magnetic declination (note that the magnetic north pole is drifting rapidly north these years, so make sure your dec value is up to date up to date) to gross align my RA axis and set the Declination based on where I am on the earth's Latitude.

However, I never do Polar Alignment at all and only use Drift Alignment, mainly because I can't see anything north of me and I've never had much luck doing Polar alignment with a polar scope. Drift Alignment takes less than an 1 hour start to finish now to get zero polar drift over a 5 minute period. I just hook up the camera center it on a  due south or due east star (depending on axis measuring), make sure the cameras X axis is parallel the real RA axis and then uses Astro IIDC's Analyze RA-Dec Tracking to measure the changes. You do need to have an motor driven scope to do Drift Alignment though.

The basic theory of it are described here

http://members.aol.com/ccdastro/drift-align.htm

http://www.darkskyimages.com/theory.html

and here (in a utube movie)

http://www.youtube.com/watch?v=4OtelWKWntc

For actually doing it I found these links

http://www.astrocruise.com/polarnew.htm

http://www.darkskyimages.com/gpolar.html

http://www.astropix.com/HTML/I_ASTROP/TRACKED/POLAR.HTM

work really well.

Hope that helps..

Milton J. Aupperle