A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Gary LaPook
Date: 2011 Jan 22, 18:12 -0800
|Since I made a larger water filled artificial horizon yesterday I decided to give it a try today and compare the accuracy of the water artificial horizon with the accuracy of the mercury horizon. I took three series of lower limb sun sights with my Tamaya Jupiter. I used the standard 4X40 scope for two series, one of 5 shots which had a sigma of 0.4037 and the second series of 6 shots that had a sigma of 0.0752. Combining these 11 shots resulted in a sigma of 0.3605. I took the third series using the inverting scope from my SNO-T (which fits in the Tamaya scope mount) to see if the higher magnificaton would produce greater accuracy. I took 5 shots which had a sigma of 0.4266 so was no better than with the 4X40 scope. |
A couple of days ago I took similar sights with the mercury horizon. Using the 4X40 scope for 5 shots resulted in a sigma of 0.4219 and with the inverting scope for 18 shots resulted in a sigma of 0.3308.
Based on these experiments it doesn't appear that there is a significant difference between the two scopes or between the two artificial horizons when shooting the sun. Off course the mercury is better for dim stars.
BTW, is was 73° F here today in southern California so I didn't have any problem with the water freezing in the artificial horizon.
--- On Sat, 1/22/11, Gary LaPook <glapook---.net> wrote: