NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Al Stewart
Date: 2024 May 12, 06:32 -0700
Hi Frank,
sorry to come in late on this reply... for index error test of whole horizon mirror, I use the same "Bauer" method as with traditional split-view mirrors... careful direct observation of Sun using dark scope eyepiece, record Hs with reflected image of Sun below direct image limb-to-;imb, and then again above, then average the two readings. A positive increment (ON the arc) has to be subtracted, etc.
For my 1983 Tamaya MS-733 with "Univision" whole horizon mirror, the Index error has been consistently 0.4' ON the arc for the last couple of checks done.
I prefer to use the whole horizon scope for daytime measurements, and the traditional for stars... like 'em both! I have not tried the half-width glass mirror with no clear portion.
Yours aye,
Al Stewart
JAMAICA
