Re: ppp averaging and circular error of probability

[Gary E. Miller]

Yo Hans!

On Sun, 11 Sep 2022 20:03:15 +0200
Hans Mayer via <gpsd-users@nongnu.org> wrote:

> > The word probable shows up because this is a method to estimate the
> > underlying probability distribution of the measurement process.  
> 
> But isn't it that a new measured point would fall into the circle
> CEP99% with a possibility of 99% ?

"Past performance is no guarantee of future perfocemance.?

I would only assume that if I had a year of measurements.  Sideral drift,
seasonal ionosphere changes, etc.

> > Ignoring the 3 day CEPs for now as suspect, the CEP50 is saying that
> > half the observed points are within 0.6m of the mean.   That's
> > actually great.  You are using a dual-frequency receiver, and I'm
> > guessing have an outside antenna -- but you didn't explain antenna
> > and sky view: please do.  
> 
> As antenna I use the recommended multi-band active gnss antenna 
> HAB-ANN-MB-00-00 with SMA Connector from ublox.

Good antennas.  remember their are two versions of the AMM-MB, and you need
to right one for your receiver.   I think yours is the right one.

> If I look for satellites with an elevation <= 1 degree I see some of 
> them over a 24 h period.
> 
> So it seems I can look quite near the horizon

Only if you change the elevation mask in your receiver configuration.

> > You didn't explain what mode
> > you are running the receiver in.

A ubxtool dump of your receiver config would be noce.  If nothing else we
can see your elevation mask.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  Tel:+1 541 382 8588

            Veritas liberabit vos. -- Quid est veritas?
    "If you can't measure it, you can't improve it." - Lord Kelvin

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