
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Happy Equinox Day
From: Bill B
Date: 2007 Mar 22, 02:24 -0400
From: Bill B
Date: 2007 Mar 22, 02:24 -0400
> From: "P F"> Over a few minutes spanning LAN there is very little change in the > body's altitude - they used to say the sun tends to "hang in the sky" > at this time. > > So differences in recorded altitude over those few minutes are mostly > caused by random errors in observation. By comparing a graph of them > with your horizontal line it may be possible to derive a better > altitude to adopt for calculation of your latitude than any of the > recorded sights (see: "An example of a slope", 10 March 07) . Excellent point from a practical standpoint IMHO. You may recall a long series pd posts on averaging years ago where the academic viewpoint claimed that averaging should be avoided near LAN. In extreme cases I agree. For all practical purposes given the accuracy claims for GHA and declination in the N.A., and sextant accuracy, what's the big deal? Bill --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To unsubscribe, send email to NavList-unsubscribe@fer3.com -~----------~----~----~----~------~----~------~--~---