[time-nuts] Common-View GPS Network

[Brooke Clarke]

Hi Poul:

Once you know the rise and set times (where the signal is stable) in sidereal time for each SV# you can simply 
enable/disable them based on time.
I think this may be a better approach than having a mask angle based on each degree of azimuth.
Keeping track of a rise and set time for each SV# is an order of magnitude less data than a 1 deg elevation mask.

Remember that each GPS satellite repeats it's ground track, that's to say that from a fixed antenna each satellite will 
always follow the same path in the sky.
This was how/why the GPS orbit altitude was chosen.
That's why I asked for a Sidereal time plot for the Thunderbolt. On a standard time position  plot the satellites appear 
to change paths.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

Poul-Henning Kamp wrote:
> 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.
>