Hi Steve,
I've followed you over to the General section. I am starting to educate myself on the subject. I assume that someone will move the initial replies to General also.
It appears that the Star Analyzer and the ISIS software are the essential pieces, and the Star Analyzer is mounted in the optical path at the CCD or camera focal point. Is that right? If I understand your question, you are wondering how PI can be used to get the most information out of the image.
I may be getting ahead of myself, but can spectroscopy be used to measure red-shift?
Dave