NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Time of meridian passage accuracy
From: John Huth
Date: 2009 Sep 26, 19:02 -0400
From: John Huth
Date: 2009 Sep 26, 19:02 -0400
Doug, George -
Thanks for the enlightening back-and-forth. I hadn't thought about this effect, but I do see the point that meridian passage does not coincide precisely with the maximum altitude.
The original poster quoted Bowditch:
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use the time listed under the “Mer. Pass.” column to estimate LAN unless extraordinary
My reading of Bowditch is that they're concerned about classic sextant/chronometer work, so the 0.8 arc-minute difference seems to be consistent with this, although I imagine one can strive for the best accuracy by making a small correction. 0.8 begins to sound like extraordinary accuracy, given my personal skills with a sextant.
John H.
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Thanks for the enlightening back-and-forth. I hadn't thought about this effect, but I do see the point that meridian passage does not coincide precisely with the maximum altitude.
The original poster quoted Bowditch:
--------------------------------------------------------------------------------------------------------------------------------------------
use the time listed under the “Mer. Pass.” column to estimate LAN unless extraordinary
accuracy is required.
-----------------------------------------------------------------------------------------------------------------------------------------My reading of Bowditch is that they're concerned about classic sextant/chronometer work, so the 0.8 arc-minute difference seems to be consistent with this, although I imagine one can strive for the best accuracy by making a small correction. 0.8 begins to sound like extraordinary accuracy, given my personal skills with a sextant.
John H.
--~--~---------~--~----~------------~-------~--~----~
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
