NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Chronometer Suggestions
From: Lu Abel
Date: 2009 Jan 06, 11:05 -0800
From: Lu Abel
Date: 2009 Jan 06, 11:05 -0800
Irv and Bill:
It's a MAXIMUM of 1 NM for every 4 seconds, not a minimum.
If the body you're sighting is directly north or south of you, even a fairly significant time error would result in a very minimal shift in the LOP produced by the body (the extreme example is Polaris). On the other hand, if the body you're sighting is directly east or west, then it's Geographic Position is moving by 1 NM every four seconds and any LOP developed from that sight would be off by 1 NM for every four seconds of clock error.
Lu Abel
Irv Haworth wrote:
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It's a MAXIMUM of 1 NM for every 4 seconds, not a minimum.
If the body you're sighting is directly north or south of you, even a fairly significant time error would result in a very minimal shift in the LOP produced by the body (the extreme example is Polaris). On the other hand, if the body you're sighting is directly east or west, then it's Geographic Position is moving by 1 NM every four seconds and any LOP developed from that sight would be off by 1 NM for every four seconds of clock error.
Lu Abel
Irv Haworth wrote:
Minimum of 1 NM for every 4 seconds..( a quick answer)..Irvin F HaworthW, Van BC Canada
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of William Sellar
Sent: January 6, 2009 5:05 AM
To: NavList@fer3.com
Subject: [NavList 6931] Re: Chronometer Suggestions
As a beginning celestial navigator, I am wondering how much time and watch accuracy is actually required for practical navigation. Can we predict how many miles off one would be for every second of time error?Bill
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Navigation List archive: www.fer3.com/arc
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