[time-nuts] Common-View GPS Network

Poul-Henning Kamp phk at phk.freebsd.dk
Tue Apr 16 03:55:49 EDT 2013


In message <A687BF7F4A1642E8BA7EDDA7432A3969 at pc52>, "Tom Van Baak" writes:

>When you look at the actual clock solutions (which are in the @@Hn
>message) you will be surprised at the variance. 

A lot of that variance is because the position-hold coords are wrong.

I tried using the @@Hn data to "sneak" up on the right coords and got
some pretty good results, but the process too forever (as in: Months)

See:
	http://phk.freebsd.dk/raga/sneak/

The improvement in the finished timing solution from the oncore is
quite marginel because on average you have satellites on all
sides of your antenna and the errors mostly cancel out.

The notable exception to that is where I live: at 56N.

56N is at the top of the GPS orbits, so satellites never venture
north of me, and I'm not sufficient north to have any benefits from
the satellites which rise above Canada/Alask on the other side of
the north pole.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


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