Yo Hans!

On Fri, 21 Nov 2025 23:04:28 +0100
Hans Mayer <[email protected]> wrote:

> So I decided I give it a try again after years.
> My environment is an U-BLOX ZED-F9P (PROTVER=27.12)
> with an antenna HAB-ANN-MB-00-00 fix mounted on the top of the roof
> of my house.

Which F9P model?  L1/L2, or L1/L5.  With or without SBAS?

Did you verify the correct signals were enabled.  As in:

    ubxtool -g CFG-SIGNAL

https://gpsd.io/ubxtool-examples.html#_checking_constellations_gen9

Got the dynamic model set to fixed?  Like this:

    ubxtool -g CFG-NAVSPG-DYNMODEL,0

https://gpsd.io/ubxtool-examples.html#_gen9_7

> I did run twice a measurement as described in example 1 of the man
> page. The first with 12 hours 46 min and the second with 12 hours.
> This was the command line I used:
> gpsrinex -i 30 -n  1440 --ant_num 2 --observer mayer --ant_type 
> HAB-ANN-MB-00-00 localhost:gpsd:/dev/serial0

Looks good.  But the ant-type is not one of the "official" choices.

> When I got the first result I was impressed.
> I got a 95% sigma of 12 mm for lat and 10 mm for long.
> So I started a second run with 12 hours.
> There I got 15 mm and 22 mm as result of sigma. Not so bad I thought.
> But then I calculated the distance between this two geolocations.
> And the result was disillusioning. The distance is 164 mm , far away
> of this 95% sigma.

Wow.  First I have heard of anyone doing that.  Disappointing.  I'll
have to give that a try, I nevver thought to compare two runs.

> About 2 years ago I tried to find the accurate position by averaging.
> I run 12 times 24 hours measurements.
> When I calculate the distance between this result and the gpsrinex 
> result I get more than half a meter.
> So I am not sure what I should believe what is true and what is wrong.

"A man with more than one watch never knows what time it is."

There is a USGS benchmark near me, for a long time I thgouht I should
run a test with my antenna over the known position.  Uh, oh.  Looking
at that benchmark, it does not have any accuracy specified...

> And there is another question.
> At the Canadian PPP service I read now they support GLONASS and
> Galileo too.

So they say.  Did not work for me last time I tried.

> So I left both systems in the config enabled. But the final report 
> didn't list them.

Dunno what's with that.  I have emailed them a few times.  But the
operators have zero clue as to what the program they run actually
does.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        [email protected]  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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