Thanks Ogygos,

Much appreciated. Supposedly the Cybersky demo program took proper motion and all of the other variables into account, but I guess I will reconsider the $32.00 purchase price. The 39.282 deg angle you got is almost exactly the same as the 39.29 deg angle for a slope of 9/11, and that is what I think was the intended mean angle anyway, as explained on the webpage I linked above.