Recording raw data with LG290P

IoT Modules GNSS Module
1

Hello,
I am writing to you because I intend to try post processing (PPK) with LG290P and use online service from Canada.
I therefore need to record raw data for a few hours.
I have these questions:
-how do I set LG290P: in base mode or in rover mode!?
-do I also need to set other parameters?
To store the position coordinates can I use “sw maps” software that records raw data in ubx format?
The ubx data can be converted to rinex if I remember correctly.
With my previous gps module (f9p) I operated in the above way but is it also correct for lg290p?

Do you have any suggestions on this matter!’

Thanks
AF

2

Hello Sir,
1, LG290P is in rover mode by default. You could use PQTMCFGRCVRMODE command to select rover or base mode, PQTMSAVEPAR to save into flash (maintains after power cycle), then restart to take in place.
2, PQTMCFGPROT to check if current port support RTCM or NMEA feature. Generally, in rover mode, NMEA output is enabled and RTCM output (MSM4/7, EPHM, 1005 etc.) is disabled and can be enabled by command $PQTMCFGMSGRATE.
3, In base mode, accurate position should be set by PQTMCFGSVIN command manually or automatically.
For details, please refer to protocol doc.
Quectel_LG290P(03)_GNSS_Protocol_Specification_V1.0.pdf (537.0 KB)

3

Thanks @Berton.Peng-Q.
I apologize for the bad wording of the question.
My question is about the mode and settings I should use with lg290p to store the raw data and then transfer it to the Canadian post processing service.
Is there anyone in this forum who can tell me how I can solve the storage of the raw data and with which software!?
Thanks and sorry for the inconvenience
AF

4

Salve, Alberto,
neanche io ho compreso cosa intendi fare; comunque se hai dei punti da battere come libretto di campagna, puoi loggare le posizioni in formato rtcm e procedere a trasformarli in rinex…
Bisogna settare il modulo (non ricordo se poi la frequenza è di 1Hz),successivvamente usare rtklib e non il canadian service, cioè RTKPOST, usando sia i log del rover che le correzioni del ntrip anche essi loggati e trasfomati in rinex con anche le effemeridi magari precise (finali) di igs, tutti questi dati in pasto a rtkpost consentono la soluzione post_processing…
Ci sono esempi di impostazione in rtklibexplorer oppure delle lezioni in gis in (italiano).
Marco

5

Thank you so much @bamarcant!
How do I log the raw data!?
I have to act in rover or base mode.
What I have to do is “simply” collect the raw data after a few hours of recording in single mode and then send them to the online ppk service in Canada. A few years ago with gps f9p (ublox) and the “sw maps” software I succeeded in the operation: I first had to enable the RAWX and SFRBX messages via ucenter.
I then converted the ubx files containing the raw data (recorded by sw maps in the raw folder) to rinex before uploading them to the Canadian portal (all of the above if I remember correctly).
I was wondering if it is also possible to do the same thing with LG290P, possibly enabling some messages.

Thank you again for your interest. AF

6

non fa differenza, importante estrapolare RTCM (che sono i raw per lg290p)
quindi attivarli, se in modalità base lo saranno di default mentre in rover mode bisogna:
$PQTMCFGMSGRATE,W,RTCM3-10XX,1,0*checksum
cioè tutti quelli del gruppo MSM7
esempio

$PQTMCFGMSGRATE,W,RTCM3-1077,1,0*40
$PQTMCFGMSGRATE,W,RTCM3-1087,1,0*4F
$PQTMCFGMSGRATE,W,RTCM3-1097,1,0*4E
$PQTMCFGMSGRATE,W,RTCM3-1017,1,0*46
$PQTMCFGMSGRATE,W,RTCM3-1027,1,0*45
$PQTMCFGMSGRATE,W,RTCM3-1037,1,0*44

se vuoi anche
1019 Input/Output GPS Ephemerides
1020 Input/Output GLONASS Ephemerides
1041 Input/Output NavIC/IRNSS Ephemerides
1042 Input/Output BDS Satellite Ephemeris Data
1044 Input/Output QZSS Ephemerides
1046 Input/Output Galileo I/NAV Satellite Ephemeris Data
esempio
$PQTMCFGMSGRATE,W,RTCM3-1019,1*54 etc…
Per loggare basta salvare in file…
naturalmente il modulo deve dialogare con il telefonino sul quale è il programma es. swmaps.
Il file ottenuto va trattato come raw data con la specifica di rtcm3.Ho postato anche il link al video…

immagine
immagine474×432 13.7 KB

se hai un ntrip non hai bisogno di Canada
basta inserire i dati in rtkpost:
immagine
immagine555×380 11.2 KB

7

Thanks @bamarcant
for the useful information.
Unfortunately I have little knowledge on the subject and therefore I have not understood well how to save the logs!?
Obviously I have to save them (the logs) on my cell phone that I connect via bluetooth to the LG290P GPS.
If I’m not mistaken with SW MAPS the raw data are stored inside the .ubx file in the RAW folder of the app on the cell phone!? Do I have to use another app to store the RTCM3 messages!?

thanks
AF

8

In swmaps, impostare generic nmea e spuntare log to file,
lo vai a cercare e lo rinomini es. file.rtcm3 che poi converti in rinex…
Io preferisco lefebure che ha ip/tcp oltre a bluetooth
dal quale si può loggare sia ntrip che il rover…in receiver settigs della app “Save GPS data to file”
“Save Ntrip data to file” …

9

Ok @bamarcant thanks for the assistance.
(I apologize for the late reply but the forum “punished” me for excessive activity for 14 hours)
So on LG290P I activate the RTCM3 messages then through swmaps I record them. Then I enter the mobile phone and the raw folder of swmaps and I rename the.ubx files to.rtcm3 files that I will later convert to rinex.
I still have to understand this: when you talk about also logging the ntrip data (if I’m not mistaken the corrections) with ntrip lefebure that I sometimes use with qfield or merge maps. Question: but if I’m in “single” mode why do I have to record the raw data why do I have to log the ntrip data (which is not activated)!? I hope I haven’t said heresies but obviously I’m not an expert in post processing.
Where am I wrong?
Thank you very much for everything
AF

10

A questo serve il post processamento…
quando non hai la possibilità di connetterti (o non vuoi) a un servizio regionale di correzione, puoi comunque usare anche i loro dati, basta scaricare le loro osservazioni del periodo esatto coincidente al rilievo e caricarli proprio per eseguire il post processamento, otterrai un rilievo al millimetro,cioè un sistema base/rover non rtk ma posticipato…
P.s a causa di alcuni balordi che postano schifezze, i moderatori hanno fatto di tutte erbe un fascio!
Io almeno ho postato un link al video coerente,guardalo.

11

Ok @bamarcant.
Thanks for the link to the video about “post processing”.
What I didn’t understand though is the usefulness of recording ntrip data for example via ntrip lefebure!?
Also considering that I’m operating in “single” mode without data correction!?
Sorry but I’m inexperienced in GNSS and I hope I didn’t say something stupid!
Thanks again for your availability and interest.
Greetings
AF

12

why do they keep saying to use SVIN for “accurate position”
it’s NOT accurate at all, it’s no better than what you get from your phone.