Ublox F9p Precise Point Positionig fail

Hello,

I succesfully built a Base-Rover system with twoF9P breakout boards, two Artemis Redboards, Lcd screens and SD card reader, and the two communicate via LoRa radios flawlessly, sending RTCM and allowing to achieve RTK-Fix position with the rover, after surveing-in with the Base.

Image:

https://drive.google.com/file/d/1R0gZ4r … ulloy/view

I then tried to post-process the logged data with RTKLib, through the RtkExplorer fork, to perform PPP.

The steps I took are as Follows:

o Enabled logging of base RXM-RAWX and RXM-SFRBX to SD with the Artemis.

o Downloaded the *.ubx file to the PC and converted it with “RTKConv” utility to *.obs, *.nav and *.sbs files.

At this point the “RTKPlot” utility successfully shows the reception of satellite pseudoranges (Also, u-center shows them as RAWX and SFRBX messages in the original .ubx files").

o Downloaded "*.sp3 ephemeris and *.clk satellite clocks with “RTKGet” covering my raw data acquisition period.

o Opened “RTKPost” and set it as follows:

  • The converted “.obs” file in the “RINEX OBS” input

  • The converted “.nav” file in the input below

  • The downloaded".sp3" file in the next input

  • The downloaded".clk" file in the next input

  • The converted “.sbs” file in the last input

I set “PPP Static” and “Precise Ephemeris” in the Setting1 tab, and “Single” as Solution for static mode in the Output tab.

However I get “Q=0” during processing and the generated *.pos file is empty:

% program : RTKPOST ver.demo5 b34b

% inp file : C:\Users\Matteo - Fisso SSD\Desktop\Test UBX\vecchi\12111129.obs

% inp file : C:\Users\Matteo - Fisso SSD\Desktop\Test UBX\vecchi\12111129.nav

% inp file : C:\GNSS_DATA\2187\igr21876.sp3

% inp file : C:\GNSS_DATA\2187\igr21876.clk

% inp file : C:\Users\Matteo - Fisso SSD\Desktop\Test UBX\12111129.sbs

% obs start : 2021/12/11 11:28:46.0 GPST (week2187 559726.0s)

% obs end : 2021/12/11 16:52:07.0 GPST (week2187 579127.0s)

% pos mode : PPP Static

% solution : Forward

% elev mask : 15.0 deg

% dynamics : on

% tidecorr : on

% tropo opt : SBAS

% ephemeris : Precise

% navi sys : GPS GLONASS Galileo QZSS BDS

% antenna1 : ( 0.0000 0.0000 0.0000)

%

% (lat/lon/height=WGS84/ellipsoidal,Q=1:fix,2:float,3:sbas,4:dgps,5:single,6:ppp,ns=# of satellites)

% GPST latitude(deg) longitude(deg) height(m) Q ns sdn(m) sde(m) sdu(m) sdne(m) sdeu(m) sdun(m) age(s) ratio vn(m/s) ve(m/s) vu(m/s) sdvn sdve sdvu sdvne sdveu sdvun

I put a link to the original “.ubx” reconding and ask if someone could kindly check it and confirm if it contains al the necessary data to perform PPP:

https://drive.google.com/file/d/18dZEIA … sp=sharing

If it does then, what is that I am missing in the post-processing?

Thanks in advance

Image link:

https://drive.google.com/file/d/1R0gZ4r … sp=sharing

Artemis source code:

https://drive.google.com/file/d/1ctqhzf … sp=sharing

I see both of those links are listed as in your trash. I’m just about to start with a uBlox f9p or f9k from SparkFun. If you’ve solved the problem, I’d be interested to know how and what was involved. If you haven’t I’d be happy to put another set of eyes on it as I’m planning to do something similar really soon.

Yes, it looks like I solved the problem: the steps involved were to convert the *.ubx files to .obs,. nav, .sbs etc. with RtkExplorer’s RtkLib/RTKConv version but do the post processing with the RTKPost from the original RTKLib 2.4.2 (not the 2.4.3). I am still experimenting though, so, If you like, i’ll be happy to share my experience with you.

Yes, I’d like that. I’m not sure how to get in touch other than here in the forum. Also – I wonder, is there any way to set alerts when a post gets a new reply?