Cannot get FIX Position using Ublox LEA-6T recievers

[geogeek11]

I'm testing this Ublox LEA-6T GPS receiver with RTKLIB, using positioning mode Single, i cannot get FIX Position even after more than 45min of observation. but with u-center v8.12 it give me a fix position in less than 2 min. this is the RTKLIB log of 46 minutes of observation without fix position. https://drive.google.com/file/d/0BwyGQjPp56zjY25wVjZoU1U1OUk/view

i've tested the version 2.4.2_p9 , 2.4.1 , 2.4.2 . none of them works .

i'm available to help you with any other information to fix this bug.

Thanks in advance.

[DavidKelleySCSC]

If you are in the single mode of rtklib, you will never ever see it move to fixed/float mode as that will only occur with the correct mode and a suitable base station. By contrast the u center tool, and the 6T itself, is always in what rtklib calls the single mode. I can not read your log file from this pda, but the foregoing is alwaya true. If you see the 6T raw data getting used to produce a single type position estimate, try and find a local (the closer the better) base station you can use and then try with one of the rtk modes. Also make sure you get orbital data as part of your solution set as well.

Regards, David Kelley, from a tablet device, please excuse my spelling

-----Original Message----- From: geogeek11 notifications@github.com To: tomojitakasu/RTKLIB RTKLIB@noreply.github.com Sent: Sun, 19 Oct 2014 3:24 PM Subject: [Spam] [RTKLIB] Cannot get FIX Position using Ublox LEA-6T recievers (#55)

I'm testing this Ublox LEA-6T GPS receiver with RTKLIB, using positioning mode Single, i cannot get FIX Position even after more than 45min of observation. but with u-center v8.12 it give me a fix position in less than 2 min. this is the RTKLIB log of 46 minutes of observation without fix position. https://drive.google.com/file/d/0BwyGQjPp56zjY25wVjZoU1U1OUk/view

i've tested the version 2.4.2_p9 , 2.4.1 , 2.4.2 . none of them works .

i'm available to help you with any other information to fix this bug.

Thanks in advance.

---

Reply to this email directly or view it on GitHub: https://github.com/tomojitakasu/RTKLIB/issues/55

[geogeek11]

Thanks a lot Mr. David Kelley, for your quick and detailed answer, for the moment i cannot use any real base station, but i've a couple of Ublox LEA-6T GPS receivers, do you think it's possible to let them work in RTK mode in RTKLIB by using them both (one as base station and the other as rover), or i should use real base station (High end GNSS like trimble ....) .

Thanks in advance.

Best Regards

ADIBA Abdelilah

[DavidKelleySCSC]

Others on this list do this and can perhaps advise better on the effect of using ublox as base station. But you can always capture your ublox raw messages, convert these with RTKLIB to a RINEX file and submit them to places like the NRCAN folks and thier PPP service to see what you would get. Where is your operational area that yoo can not find a semi public reference station to use?

Regards, David Kelley, from a tablet device, please excuse my spelling

-----Original Message----- From: geogeek11 notifications@github.com To: tomojitakasu/RTKLIB RTKLIB@noreply.github.com Cc: DavidKelleySCSC DavidKelley@ITSware.net Sent: Sun, 19 Oct 2014 4:16 PM Subject: [Spam] Re: [RTKLIB] Cannot get FIX Position using Ublox LEA-6T recievers (#55)

Thanks a lot Mr. David Kelley, for your quick and detailed answer, for the moment i cannot use any real base station, but i've a couple of Ublox LEA-6T GPS receivers, do you think it's possible to let them work in RTK mode in RTKLIB by using them both (one as base station and the other as rover), or i should use real base station (High end GNSS like trimble ....) .

Thanks in advance.

---

Reply to this email directly or view it on GitHub: https://github.com/tomojitakasu/RTKLIB/issues/55#issuecomment-59670064

[DavidKelleySCSC]

Geogeek11: I see there is an IGS listed reference station in RABAT (mount point RABT), perhaps you can use that one if it is available to you live.
The data which you posted a link to seems to be raw uBlox data and NMEA183 sentences, the trace files from RTKLIB can be of more value in debugging. To capture the data for post processing use, or to feed the obs data into RTKLIB (live live use of for post processing with RTKCONV) you will need to cause uBlox to output the 'raw' message which I did not see in there. You will also need that message for use in RTKNAVI for any live tinkering and you can poke around with the uCenter tools to cause it to be output.

[geogeek11]

DavidKelleySCSC:

Thanks a lot for your answers. I've tried to capture RAW data using RTKNAV and diffferent positioning modes (Single, DGPS, Kinematic , Static, Fixed .. ) , and i save log with .ubx format , then i cannot convert it to RINEX using RTKCONV, it doesn't give any errors but the conversion is not done. Any idea about how to to convert obsevation to RINEX. i'm newbie in RTKLIB.

Here you will find log data from RTKNAV and log data from Ucenter https://drive.google.com/file/d/0BwyGQjPp56zjc2pqOUJCRFM1NTg/view?usp=sharing

i'would like to have RINEX data for Demo purpose, then i think i could use this this receiver as Rover, in DGPS mode with GNSS base. without data link.

[astrodanco]

I've tried to capture RAW data using RTKNAV

Capture with STRSVR, then use RTKCONV to convert the raw data to RINEX. STRSVR doesn’t care what format the raw data is in. You do need to tell RTKCONV that it’s u-blox format.

[eltorio]

Looking at the log, I’m not sure it is pure UBX raw, since it contains hundred NMEA sentences

Le 21 oct. 2014 à 15:28, astrodanco notifications@github.com a écrit :

I've tried to capture RAW data using RTKNAV

Capture with STRSVR, then use RTKCONV to convert the raw data to RINEX. STRSVR doesn’t care what format the raw data is in. You do need to tell RTKCONV that it’s u-blox format.

— Reply to this email directly or view it on GitHub https://github.com/tomojitakasu/RTKLIB/issues/55#issuecomment-59926747.

[astrodanco]

Looking at the log, I’m not sure it is pure UBX raw, since it contains hundred NMEA sentences

You want pure u-blox format raw data containing only RXM-RAW and RXM-SFRB messages. Use u-center->view->configuration view->MSG to enable those two messages and disable everything else on the port in question. NMEA is of no use here.

[geogeek11]

Thanks @astrodanco for your advice. i've tried so hard to alter "configuration view" settings but i cannot for some reason in the ucenter software, the combobox in configuration view get flicking when the device is connected so i cannot update MSG values , so can you help me please by sending me a GNSS configuration file containing that settings "ONLY RAW DATA" to import it into my device, here you will find my GNSS configuration file so you can check what's wrong with my configuration.

https://drive.google.com/file/d/0BwyGQjPp56zjbWxuQlE1N0FiWGc/view?usp=sharing

Thanks in advance

[DavidKelleySCSC]

I see astrodanco https://github.com/astrodanco has answered this and getting the UBX RAW message content is the key. Personally I am still confused by the set up process of uCenter (we have programmed some scripts to deal with it here) but you have to both tell it to send that message to a port (i,e uart1) and then tell the port to output it. Extra message types will not hurt RTKLIB (it ignores them) but it does make the file harder to read. Its binary so look fo rthe UBX tag at the start of each line and ten see if the RTK convert tool can process it.

Your phrase "view get flicking" is unclear to me but GREATLY concerns me. The uCenter SW has a rather annoying habit of showing the user options and commands that do not work for the model that it is plugged into. When you select one of these it does not say something plain like "not supported" but jumps to some other command leaving you unsure what just occurred. Perhaps this is what you meant? In a prior post you stated you were usiing a "Ublox LEA-6T GPS" and that should work. The RAW data output is fully supported in the 6T unit, but not in some (most?) other models. You can look around on the web and find ROM patches that can be applied to some of these to allow RAW data streams out (hence making them suitable for RTK use), but I have not done it myself (but we are certainly going to try it).

Per your other post, lots of folks use the post processing method to "improve" the field data in the way you describe, in fact 25+ years ago that was the std way. Most truly precise user campaigns still do it today for that extra bit that prices orbits can give.

Regards, David Kelley

On 10/21/2014 3:05 PM, geogeek11 wrote:

Thanks @astrodanco https://github.com/astrodanco for your advice. i've tried so hard to alter "configuration view" settings but i cannot for some reason in the ucenter software, the combobox in configuration view get flicking when the device is connected so i cannot update MSG values , so can you help me please by sending me a GNSS configuration file containing that settings "ONLY RAW DATA" to import it into my device, here you will find my GNSS configuration file so you can check what's wrong with my configuration.

https://drive.google.com/file/d/0BwyGQjPp56zjbWxuQlE1N0FiWGc/view?usp=sharing

Thanks in advance

— Reply to this email directly or view it on GitHub https://github.com/tomojitakasu/RTKLIB/issues/55#issuecomment-60006808.

[geogeek11]

Thanks a lot @DavidKelleySCSC

The model of my device is Ublox LEA-6T-1-001 and it's using FW 7.03, i've searched for a patch as you said but i've found nothing, i've tried to activate RAW output but without a success, i've the same problem like in this video. http://youtu.be/5zA-cVgrk_o

here is my GNSS configuration file https://drive.google.com/file/d/0BwyGQjPp56zjbWxuQlE1N0FiWGc/view?usp=sharing

Any Help please i need to activate Raw output

[DavidKelleySCSC]

geogeek11:
First, you should not need any patch, this is only for other models
such as the NEO-6M that (by design) do not output raw observations. 
I think people's motivation there is one of cost savings. 

Second, with LEA-6T-1-001 (or with a box marked EVK-) you should
have the newer 001 chip inside but some have an older -000 chip
inside them and revision 6.x firmware.  With rev 7.x onward the
devices will make use of older RTCM Rev 2 types 1 and 9 messages in
its internal filter, while with earlier releases these devices will
not in fact use any RTCM corrections.  Some of the small silver
EVU-6T-001 evaluation units have that chip in side (and hence have
this limitation), but those still do RTK correctly as well. it is
best to look inside and be sure.  This a small technical point that
uBlox does not draw attention to and I had to speak with the rep
several times to understand better.  But you want to do an external
RTK style filter, so as long as you can get raw code and carrier
data, the internal navigation filter will not be of concern for your
application.  

Back to the main issue...    The video you have posted does show
that uCenter is doing what I feared and what you called flicking. 
So the core issue to resolve is why is it you can not set this
message type to be output.   The coupling between selecting a
message to send and ensuring that a given port sends it remains
confusing to me on this chip.   I am afraid my lack of understanding
the internals of this one make it a guessing game, but I will also
ask co worker for any 'recipe' we might have.   You need to be able
put the "UBX RXM-RAW" message out one of the ports (ideally on
UART1).  

If you go into the message dialog are you able to see the raw
messages in uCenter at all when the device is working? If that is
occurring then the message is leaving the device and making it to
uCenter on you PC, perhaps over the USB port.  You will not see any
SV content there unless there are tracked SVs, but you will see the
binary display below it changing even with no SVs in view. 

Is the port itself active and set up to send this type of content?
Look under the Configure dialog for PORTS and make sure that the
port you use is set to send "UBX" type messages.  

Those are to only two things that occur to me to suggest.
My apologies to the list for tagging this thread as spam in my prior
replies
Regards, David Kelley

On 10/22/2014 6:55 AM, geogeek11 wrote:

  Thanks a lot @DavidKelleySCSC 

The model of my device is Ublox LEA-6T-1-001 and it's using FW 7.03, i've searched for a patch as you said but i've found nothing, i've tried to activate RAW output but without a success, i've the same problem like in this video. http://youtu.be/5zA-cVgrk_o

here is my GNSS configuration file https://drive.google.com/file/d/0BwyGQjPp56zjbWxuQlE1N0FiWGc/view?usp=sharing

Any Help please i need to activate Raw output

---

Reply to this email directly or view it on GitHub: https://github.com/tomojitakasu/RTKLIB/issues/55#issuecomment-60087936

[geogeek11]

@DavidKelleySCSC Thanks a lot for your help.

I've taken a screenshot to share all the consoles in this link http://oi62.tinypic.com/xmljzo.jpg i wish that it was what you were asking for , if not i could help more to understand what's wrong.

concerning the 2nd question, i've not found where to change port, can you describe please with more steps please, to not make a mistake.

Thanks a lot

[DavidKelleySCSC]

geogeek11" I do not see any "UBxxxx" type content on the binary screen. Rather then the three consoles, use the Message-View and Configuration-View dialogs (the next two items in the view menu), I am using a uCenter rev 7 SW on a machine here but I believe the core menus are the same. [I can upload to whatever is current on another machine late today if that is needed]

In the Configure dialog, under the tree element "PRT (Ports)" select and look at the insert to the dialog. Select the port in "Target" and then select one of the options in the "Protocol Out" that has either UBX or RAW, or type in "1+2+3" which seem to means send them all (I have not seen where this is documented but it is in fact appears as the default at times).

At the same time, bring up the Message-View dialog and select the tree entry "RAW" under "RXM" under "UBX" so that you will see the raw measurements displayed. Be sure to "enable child messages" as you go to down this tree. Perhaps its time to move back to basics and confirm you can get any binary content out, for example the sub frame data. All you want to see at this point is the data changing.

Just FYI, my 9~5 gnss work will take me off line for the next 48 hours.

On 10/22/2014 11:07 AM, geogeek11 wrote:

@DavidKelleySCSC https://github.com/DavidKelleySCSC Thanks a lot for your help.

I've taken a screenshot to share all the consoles in this link http://oi62.tinypic.com/xmljzo.jpg i wish that it was what you were asking for , if not i could help more to understand what's wrong.

concerning the 2nd question, i've not found where to change port, can you describe please with more steps please, to not make a mistake.

Thanks a lot

— Reply to this email directly or view it on GitHub https://github.com/tomojitakasu/RTKLIB/issues/55#issuecomment-60128530.

Regards, David C. Kelley

[geogeek11]

Hello @DavidKelleySCSC ,

I've tried to change the parameters for port but after applying the changes a pressed send to apply the changes, the problem still not solved , i've tried to output ubx + RAW , but again i cannot enable RMX => RAW it gets always disabled

here is a screenshot of the consoles http://oi57.tinypic.com/15x35w2.jpg

[pkoundinya]

@geogeek11 I think in the Protocol Out you should have "0+1+2" and not just 0+3, although what you have makes sense.

I am using a UBX LEA 6T in my car(rover) and trying to get a Differential solution using RTKPOST and the RINEX base station info from CORS website. (http://geodesy.noaa.gov/CORS/).

But my Q in the RTKPOST output always stays at 5 and ratio is 0.0.

could you help me out with the settings for RTK post?

Thanks in advance

[erumoico]

Hello everybody, I am using u-blox LEA-6T too and I maked the command file for enable MSG (Messages) RXM-RAW & RXM-SFRB for USB and set UBX-CFG(config)-PRT(ports)-USB-Protocol out as "UBX+NMEA". Follow https://github.com/erumoico/RTKLIB/blob/master/data/ubx_l6t_raw.cmd. Maybe you find it useful.

[kbaumanis]

@DavidKelleySCSC @geogeek11 Apologies for bringing up an old thread, but the "flicking" problem you guys were discussing, was that ever resolved? I'm working with a lea-6t as well and I'm trying to turn on RXM-RAW and RXM-EPH and I'm failing to do so due to the same problem.

[DavidKelleySCSC]

Kristaps:
I do not think there is anything to resolve, only to understand. If
you are really using a 6T and not one of the others (be very sure
about that), it should be able to output raw code and carrier
data.   And if it has rev 7.x firmware, it should be able to accept
and use RTCM type 1 or 9 messages.  You can enable output of the raw
message with uCenter or with direct programming, but the uCenter
tool is certainly easier. 

I had to go re-read that thread and then speak with some engineers
here, but that outcome of that was....   The term "flicking" refers
to the uCenter software where not all features work with all
chips/products.  In a device that does not in fact support
something, the uCenter software will grey out after you select an
option or a command, visually flicking away from what you thought
you told it to do.  That is about your only GUI insight that the
command was not done. 

Good luck, David Kelley

On 7/27/2015 8:54 AM, Kristaps Baumanis
  wrote:

  @DavidKelleySCSC
    @geogeek11 Apologies for bringing up
    an old thread, but the "flicking" problem you guys were
    discussing, was that ever resolved? I'm working with a lea-6t as
    well and I'm trying to turn on RXM-RAW and RXM-EPH and I'm
    failing to do so due to the same problem.
  —
    Reply to this email directly or view
      it on GitHub.