NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Celestial Navigation at NEAF
From: Lu Abel
Date: 2015 Apr 18, 22:05 +0000
From: Lu Abel
Date: 2015 Apr 18, 22:05 +0000
It could be that the mediocre sight accuracy is due to the fact that the artificial horizon is not dead level.
What was supporting the mirror? Is there a way of checking/adjusting its levelness?
It doesn't take much -- just a minute or two of being off-level.
What was supporting the mirror? Is there a way of checking/adjusting its levelness?
It doesn't take much -- just a minute or two of being off-level.
From: Bruce J. Pennino <NoReply_Pennino@fer3.com>
To: luabel@ymail.com
Sent: Saturday, April 18, 2015 2:46 PM
Subject: [NavList] Re: Celestial Navigation at NEAF
The mirror floating in pool is really elegant. I’m jealous. I now regret all of my effort to use a steel plate with leveling screws, plus all of the other refinements I built into my “system” so I could use it on steep uneven ground etc.Simple is best. Accuracy of plus/minus 1 mile is probably happenstance good fortune. With a quality sextant I would believe plus/minus 1.5-2 miles. What is typical best accuracy with mirror or pool of fluid?BruceFrom: Robin StuartSent: Saturday, April 18, 2015 4:01 PMSubject: [NavList] Celestial Navigation at NEAFI visited the North Eastern Astronomy Forum (NEAF) at the SUNY Rockland Community College in Suffern, New York. Amongst the gathering of solar telescopes I found Gary the Astronomer offering free sextant lessons to anyone who would listen. Kudos to Gary.He was using a Davis plastic sextant and for an artificial horizon had a sheet of glass in a wooden frame floating in a pan of water (see the attached photograph). He claimed to be able to get 1 mile accuracy.Robin Stuart
Attached File:
(GaryFix_NEAF2015.jpg: Open and save)
