Message-ID: <3A8AB224.C94A2BE9@usa.net>
Date: Wed, 14 Feb 2001 17:28:20 +0100
From: "Alberto di Bene" <dibene@usa.net>
Organization: Undisclosed
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To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: GPS-Disciplined BPSK
References: <200102141551.KAA11032756@indyweb.cgocable.ca>
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Bill de Carle wrote:

>
> When removing jitter from a signal that's accurate over the long term,
> we can do better than just averaging.  By letting a counter run (e.g.
> from the oscillator we're trying to discipline) and latching it with the
> 1 PPS signal, we get the number of oscillations that have occurred from
> one second to the next.  One approach would be to simply average up a
> bunch of these and say that's the best answer.  But if we don't clear
> the counter after each 1PPS latching signal - if we just let the counter
> continue running upwards, then we can use least squares to solve for the
> *slope* of the line.  Over any given time period that least squares slope
> solution will give a significantly better result than averaging alone.
> Try it if you don't believe it.
>

Isn't that a variant of Kalman filtering ?

73   Alberto   I2PHD