A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Sean C
Date: 2016 Jun 14, 09:33 -0700
Attached are the results of some lunars I shot late last night. I graphed the sextant distances and used two calculated distances to fit a slope to them (the dashed line). Using this method, I was able to pick out one of the better observations, although not one of the best. I worked that one (the fourth observation) using the formulae from Frank's "easy lunars" page. After that, I used his online clearing app to calculate the errors for all of the observations. I PhotoShopped the red line into the graph to represent the errors thus obtained.
I suppose the difference in the slopes is due to the effects of refraction, parallax and semi-diameter augmentation. Perhaps a better fit could be obtained by either clearing all of the distances first, or working these effects back into the calculated distances. Thoughts, anyone?