[ntp:questions] garmin 18x and linux

Chris Albertson albertson.chris at gmail.com
Wed Sep 7 23:57:58 UTC 2011

On Wed, Sep 7, 2011 at 9:32 AM, Greg Hennessy <greg.hennessy at cox.net> wrote:

> I'm not even sure the USNO provided time sync to GPS is at the 2nS
> level.

This is not an accuracy issue. it is an intentional offset to account
for the earth's slowing rotation rate.  here are various time scales
and at this level they only more or less ageree as each is defined

What we are talking about when we say "accuracy" is the amount of uncertainty.

Here is another paper to read:
Slide #21 shows an older VT+ Receiver's PPS output compared to a hydrogen maser.
Slide #24 is pretty good. It shows the RMS error from a newer MT+.


Chris Albertson
Redondo Beach, California

More information about the questions mailing list