NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: GPS as a time authority
From: Douglas Denny
Date: 2009 Sep 15, 12:30 -0700
From: Douglas Denny
Date: 2009 Sep 15, 12:30 -0700
I should have added I believe the relativistic effect with the 'portable' atomic clock was, if I remember correctly, mosty due to the difference in lower gravitational field potential, spending some considerable time at 40,000 ft at 350 Knotts as opposed to zero velocity at ground level - rather than the time dilation effect due to motion which is fairly 'slow' with an aircraft. The GPS satellites have the same problem but multiplied, and if not corrected will give a discrepancy of position of some dozens of miles. I expect the high velocity of satellites might become significant in relativistic effect too. I would like to know the relative values of motion Vs. gravitational relativistic effect with satellites. I am sure I have read of it somewhere but bad memory these days is becoming an increasing problem. Douglas Denny. Chichester. England. --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
