NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Index Correction
From: Alexandre Eremenko
Date: 2007 May 6, 04:47 -0400
From: Alexandre Eremenko
Date: 2007 May 6, 04:47 -0400
Robert, I am surprised that you can determine a difference in IC before and after an observation. What sextant are you talking about? (I've heard such things about plastic sextants but not about metal ones). By how much it changes? Are you sure that it really changes (this can be a random error, rather then change due to temperature). In my case, IC does not change for months, and I could never detect any noticeable dependence on the temperature. On your statistical question: Of course, I would just take the average IC before and after, as you do. Alex. > > It is common practice to check for IC before and after a round of sights. > In my experience, they are seldom the same particularly when taking sights > under non-standard temperatures. > > Question: what correction would you apply? Generally what I do is a > combination of fudging and black magic but it usually entails simply > taking the two ICs and averaging them to arrive at a single IC that can be > applied to the entire round of sights. > > Please: I am not looking for involved statistical computations. I am > trying to determine what other navigators do in the field/at sea. > > cheers, > > Robert > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---