LG290P with v2A01: Question about PPP 5 and PPP 6 states

IoT Modules GNSS Module
1

LG290P with v2A01: Question about PPP 6 and PPP 7 states
Hello, Quectel team

I’m testing the new firmware you sent me for the LG290P with Galileo HAS corrections.

I have a question.
According to the material sent, the quality indicator is 5 with pseudo differential range, 6 with PPP in the convergence stage, and 7 is PPP with convergence achieved.
Now, what parameters must be met to enter mode 6 or 7?
How does the LG290P determine the state change?

I haven’t been able to determine changes in accuracy when switching from state 6 to state 7. I’ve occasionally obtained horizontal accuracy of less than 5 cm and post-processed fixed-point dispersion between 15 and 30 cm.
So how can I know in real time what accuracy I’m working with? Do you have any empirical relationship between the accuracy reported in the GST or PPPNAV and the actual difference at the post-processing point?
Thank you.
Regards, Angel

2

Hi @amlago

Below is the quality indicator explanation

5. After the RTK differential data is interrupted, the system will switch to pseudorange differential positioning for a period of time.

6 and 7. PPP then operate in normal PPP processing mode until the solution converges.

To enter 7 is depending on the signal strength from Galileo HAS or B2b signal, after entering 7 the error will be between 15cm~25cm

Work with PPPNAV accuracy as it will show more decimal in the error accuracy as shown below

img_v3_02ul_16291b8a-0aa6-45bd-8a09-a556928c63ix
img_v3_02ul_16291b8a-0aa6-45bd-8a09-a556928c63ix737×499 136 KB

Best regards,

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Yea, values are correct ones, but if inject rtcm the $PQTMPPPNAV resets no value, so it is intendet only for PPP… althougt protocol says
immagine
However here a pic,PPP (7) converges after 5 minutes before dgps2 or 6ppp

immagine
immagine1360×586 65.2 KB

4

Hi, states 5, 6, and 7 are very clear.
My question is more theoretical. How does the LG290p “decide” whether it’s in state 6 or 7, for example, if the reported accuracies are the same? Close to 3 or 4 cm, for instance.

In other words, the measurements the LG290p takes in state 6 at the end and beginning of state 7 are practically the same. Or at least that’s what it seems to me.
What parameters change to determine whether it reports state 6 or 7?
I hope my question is clear.
Regards

5

My take on this :
6 - processing state
7 - concluded state
When it switches from 6 to 7 :

  • processing more samples does not improve current accuracy
  • the current accuracy is within spec.
    It’s not mandatory the accuracy to improve from 6 to 7.
6

Hi @amlago

To address the question:

The transition from state 6 to state 7 is determined by the module’s internal convergence logic. This transition occurs when the module has observed stable and consistent signals over time, including parameters such as carrier‑phase ambiguities, tropospheric estimates, and receiver clock stability, which together indicate a higher confidence in the PPP solution.

It is important to note that even after the solution reaches state 7, the position standard deviation (STD) will continue to improve as additional observations are accumulated, typically converging further to approximately ~0.15 m.

In short what you are seeing is normal.

7

Thank you so much for your answers.
We’ll continue investigating and stay in touch.
Regards, Angel