|
|
Subject: Re: GPS vs WWV time.
From: Paul Hirose (paulhirose@XXX.XXX)
Date: Mon Sep 03 2001 - 20:37:32 EDT
Yes, there can be an obvious (to the eye) inaccuracy in the time
displayed on a GPS receiver. My Magellan Trailblazer is sometimes a
full second off compared to WWV time ticks. I've heard of others being
several seconds off. After all, the receiver's main job is computing
position, so updating the time display has low priority.
There's also the offset between UTC and GPS time to consider. GPS time
never has leap seconds, so the two time scales have diverged by a few
seconds by now. However, the offset is encoded in the GPS signal, and
as far as I know all but the really obsolete receivers make the
correction. My old Magellan is a '94 model and it keeps up with the
leap seconds.
I guess all you can do is repeatedly test your receiver against WWV
until you get its behavior pinned down. You may want to ask on the
sci.geo.satellite-nav newsgroup.
--paulhirose@XXX.XXX (Paul Hirose)
|