NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Time and cel nav, a stupid question
From: Lu Abel
Date: 2008 Apr 22, 08:56 -0700
From: Lu Abel
Date: 2008 Apr 22, 08:56 -0700
Bill: The time difference between your Garmin and the USNO web site is likely due to network delays (ie, the USNO sends you a time pulse at the correct time, but it takes almost a second to arrive at your computer). The other web site run by USNO, www.time.gov, says it attempts to measure network delays and compensate for them. Another source for accurate time is your cell phone. Mine only keeps time to the minute, but it very accurately rolls over at the 60-second mark. Lu Abel Bill wrote: > The current discussion on time, relativity and leap seconds is, in many > areas, well above my head. Noting the various flavors of UT (currently), an > observation and a pragmatic question for cel nav. > > The seconds readout between my GPS (Garmin GPS 76) and > http://tycho.usno.navy.mil/cgi-bin/anim > differ by about one (1) second. > > The web site (dial up modem at the moment) is nominally one (1) second > behind the GPS readout. > > Bringing it into the realm of traditional navigation, which time do I use to > set my hack watch? ;-) Potentially a quarter mile intercept difference > under ideal circumstances. > > I do not have access to a time-signal radio now. > > Bill > > > > > --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
