NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Visit to Freiberg
From: Bill B
Date: 2005 May 23, 16:39 -0500
From: Bill B
Date: 2005 May 23, 16:39 -0500
Alex That is good news, and confirms my guess that the SNO-T would be approx. plus/minus 9-seconds accurate along the arc. It also means the discrepancy you measured around 50d with the SNO-T was backlash or (operator error ;-). Approx. 0.3' to .04' backlash if memory serves. Wow! Interesting that your IC was zero, which matches the arc error at 0d. I am surprised the backlash problem did not show up in your IE checks. If spring loaded, the backlash should be almost consistent along the arc-- 0d, 50d, or 90d. Bill >> Is the 4" plus minus along the arc? > > The table of correction is > 0 10 20 30 40 50 60 70 80 90 100 110 120 > 0 -4 -4 10 6 -1 4 5 -5 4 4 3 14 > The first line in degrees, the second one in seconds. > When rounde to tenths of minutes > it never exceeds 0.1' except 2 times > when it is roughly 0.2' > > The errors I had in star distances are usually larger, > and always positive. In principle they can be attributed to backlash, > but I never measured anything after the sextant test.
