A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Mark Coady
Date: 2015 Aug 24, 18:43 -0700
I know the seaport well. My home port is in West Cove Noank. Thank you for the response. The last errors were in calculated GMT. with 2 -3 minutes TIME (GMT) error under less than ideal conditons (hazy end of day, low sun angle). I know my index correction was in error. I did quick sights after work at the end of the day without a good check on index correction. I later found slight changes. I expect better.
Doing straight altitude sights with that same sextant last summer I was getting positonal errors of <2 miles often enough to make me happy.
So far I was using straight calculator spherical trig (variations on the spherical law of cosines) to resolve relative bearing angle with semiddiamter corrected altitudes, followed by calculating true lunar distance using RBA, and computed altitudes. I understand what you say about excedssive time correction. I realize its silly. Decimal habits of an engineer die hard.
I just went through last month and worked all the sample problems in the Stark Tables. Have not used them for my own sights yet.
I will happily look at your lunar tools.
Sounds like the seaport is worth a new wander. I was a member there in the past.