I was fascinated about this article https://gpsd.gitlab.io/gpsd/ppp-howto.html Therefore I tried it.
I own a ZED-F9P from U-blox with a fix mounted antenna on the roof of my house.

I was interested in the method of averaging. The steps for a 24 hour average result are quite easy, assuming one has “gpsd” and all these tools installed.

gpsprof -n 86400  -T pngcairo   localhost:gpsd:/dev/serial0 > $FILENAME.plot
gnuplot < $FILENAME.plot > $FILENAME.png
display $FILENAME.png &

I used the standard configuration. That means I used all 6 satellites I can receive: GPS, SBAS, Galileo, BeiDou, QZSS and GLONASS. And I used “dynModel 0”. ( 0 = portable )
I have done this for 6 days each 24 hours and got the following result:

day config1 lat lon AltHAE CEP50 CEP99 EP50 EP99
sc_f9p_1d_0501_cfg01.plot 48.149295188 16.283841264 287.224 0.560 2.014 0.738 3.048
sc_f9p_1d_0502_cfg01.plot 48.149294591 16.283840758 287.417 0.736 1.784 0.721 2.980
sc_f9p_1d_0503_cfg01.plot 48.149294566 16.283840620 287.354 0.704 1.326 0.759 2.875
sc_f9p_1d_0504_cfg01.plot 48.149296214 16.283841799 287.095 0.588 1.513 0.752 2.919
sc_f9p_1d_0505_cfg01.plot 48.149295680 16.283842060 287.137 0.551 1.733 0.699 2.764
sc_f9p_1d_0506_cfg01.plot 48.149297905 16.283840979 287.696 0.607 1.603 0.723 2.985
average 48.149295690 16.283841246 287.321 0.624 1.662 0.732 2.928
deviation 1.14776e-06 5.27579e-07 0.202184 0.07065 0.2169 0.0202 0.09141

I calculated the distance between any of these results and it was not bigger than 37.2 cm.
One can say that all results are within a circle of about 20 cm radius.

The next test was to use “dynModel 2”. ( 2 = stationary )

day config4 lat lon AltHAE CEP50 CEP99 EP50 EP99
sc_f9p_1d_0508_cfg04.plot 48.149296323 16.283841385 286.960 0.740 1.987 0.829 3.173
sc_f9p_1d_0509_cfg04.plot 48.149295842 16.283841204 286.905 0.640 1.563 0.723 2.891
sc_f9p_1d_0510_cfg04.plot 48.149295943 16.283840428 287.110 0.753 1.381 0.762 3.282
sc_f9p_1d_0511_cfg04.plot 48.149294459 16.283842436 287.532 0.829 1.514 0.853 3.137
sc_f9p_1d_0512_cfg04.plot 48.149296177 16.283841876 287.672 0.832 2.139 0.801 3.160
sc_f9p_1d_0513_cfg04.plot 48.149296121 16.283841722 287.537 0.805 2.082 0.781 3.319
average 48.149295810 16.283841508 287.286 0.767 1.778 0.792 3.160
deviation 6.24298e-07 6.21336e-07 0.304118 0.06654 0.29998 0.04272 0.13737

I expected better results. But this wasn’t the case.
The maximum distance between these results was 22.2 cm. Between all 12 measurements it is 40 cm. But the distance for these averaged values for config1 and config4 is only 2.4 cm.