NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
GPS as a time authority
From: J Parsons
Date: 2009 Sep 14, 09:05 -0700
From: J Parsons
Date: 2009 Sep 14, 09:05 -0700
I think this has been dicussed before, but I'd like to be refreshed on the list's opinion: While assisting the Race Committee at a regatta this weekend, I heard the timekeepers say that they were using "GPS time." I noted that my $79 wristwatch, which I check monthly against the US Bureau of Standards atomic clock (ph: 303-499-7111) and which doesn't lose a second per month, was 8 seconds ahead of the Committee's time. I later checked the time shown on my hand-held Gartmin GPS receiver, and it agreed with my watch. The watch was also still in sync with the Bureau's atomic clock. Question: Is the time displayed by GPS receivers considered a reliable and spot-on source, up to the requirements of accurate celnav? I would think that it would be, since the GPS network depends on accurate tracking of the satellites' position at a given time, yet there was that 8-second discrepancy. Perhaps the Race Committee were simply careless about setting theior clockby GPS. Any thoughts, List Members? -John Parsons --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---