NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Calculating accurate apparent-angles between stars
From: Fred Hebard
Date: 2003 Jan 6, 16:09 -0500
From: Fred Hebard
Date: 2003 Jan 6, 16:09 -0500
Thank you George, for once again providing a lucid exposition of a problem in celestial navigation. The fact that one is doing the inverse of the usual clearing procedure had been coming in and out of focus for me, and currently was out. Borda's and Young's procedures for clearing are the reverse of the procedure you outlined, as you pointed out without explicit reference to them. I also had the ulterior motive of trying to figure out what was going on with Bruce Stark's tables, which question has been raised more than once on this list. I also would like to thank Bruce for outlining the basis of his procedure for clearing. In comparing Bruce's method to your implementation of Young's procedure, one interesting point is that Bruce does not correct for latitude when adjusting horizontal parallax for the altitude of the body. Another interesting point, which I mentioned earlier, is that Bruce's tables apparently could be adapted to standard sight reduction, with no need to interpolate and only one volume to examine. I have no idea how accurate that might be in extreme cases. Again, Thanks, Fred -- -------------------------------------------------------------------------- Frederick V. Hebard, PhD Email: mailto:Fred@acf.org Staff Pathologist, Meadowview Research Farms Web: http://www.acf.org American Chestnut Foundation Phone: (276) 944-4631 14005 Glenbrook Ave. Fax: (276) 944-0934 Meadowview, VA 24361
