Re: ppp averaging and circular error of probability

[Gary E. Miller]

Yo Hans!

On Sun, 18 Sep 2022 09:12:24 +0200
Hans Mayer <gpsd@ma.yer.at> wrote:

> >>> UBX-NAV-SAT knows nothing of multuiple signals (l1 & L2, etc.  It
> >>> is only for back compatility.  The new UBX-NAV-SIG is for use
> >>> with the newer signals.
> >>>
> >>> That is confusing gpsd.  You need to configure your u-blox
> >>> properly.  
> >> I will try to do so.  
> > You can use ubxtool to fine tune the u-blox setting.  Non-trivial,
> > but the examples work.  
> 
> I don't own the ZED-F9P very long. Therefore I didn't reconfigure the 
> u-blox very much.

"very much" could mean many things.  Did you change anything and save to
non-valatile memory?  If not, then just power cycle the device to revert
to factory defaults.

> But if I understand your documentation correct it's 
> almost always possible to reset the device and bring it into a
> default setup.

Yup.  But simplest just not to save to non-volatile memory.  Almost no
good reason to ever save changes to non-valatile memory.

> The only concern I have, if I change the speed and something goes
> wrong, how to communicate with the device.

As long as you do not save changes, then just power cycle.  Also, the USB
port has no "speed", so that always works even when you change its "speed".
The USB port is the best one to use.

> >> What I do not understand completely, why do we see the satellite
> >> statistics if gpsprof is connected to gpsd but not if gpsdecode is
> >> reading the raw file?  
> > They are different programs that do different things.  Hard enough
> > to get the gpsd clients to work with good data, much less bad data.
> >  Feel free to dig deeper if you wish.
> >
> > Can you remind me how your are running gpsd?  
> 
> /usr/local/sbin/gpsd -G -n -s 38400 /dev/serial0 /dev/pps0

Looks good, assuming the pps0 is on a GPIO pin, not associated with serial0.
38,400 will be too slow if you try to get raw data.  Just use the USB port.

With that, gpsd should have reconfigured your device not to send UNX-NAV-SAT.

> commit 24616036ca687289e80fdb9e0cf6e44ecda2585f
> 
> And I see I am several commits behind.

The latest commits are for working around Quectel Querks.  As long as you do
not have a Quectel part, you are good.  For now.

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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