teqc dos not generate NAV-RINEX-file from ubx-data

François Meyer fmeyer at obs-besancon.fr
Fri Jan 17 21:33:13 UTC 2020


Hi Helmut,

Some of us have the same problem with an ashtech Z12t that only generates 0 byte
nav files ; (you can check in the archives, the thread "Curing files with
GPS rolllover issues" april 2019, contains some info) ; primary cause
remains unclear, and then unsolved.

Bottom line : grab a nav file from another receiver (nav files are
generic for a given date they are not specific to a station).

Its only problematic if you want to process more or less in real time
but do not have easy access to third party nav data. But after 1 day, you
should find nav data easily.

Best,
-- 
fm

On Fri, 17 Jan 2020, albrecht57 wrote:

> Dear all,
>
> beeing in despair with an inexpectable problem I now dare to ask you. First of all let me tell you, I am not(!) an GNSS-expert but a math-prof at an university of education in Germany. To solve interesting real problems together with my students by the use of math, I decided to compute the GNSS-receiver-position only using pseudeo-ranges and ephemeris. So I bought a Navilock NL-6002U USB containing an ublox-chip and recorded the RAW- and EPH-data to an ubx-file, which I processed with teqc to get a RINEX-OBS and a RINEX-NAV file. In both files I find the data I need to compute the receiver-position. This worked all fine for some years since 2014.
> Now, 2020 Jan. 12., I started another try which worked fine, what means, I could translate the recorded ubx-file into the needed NAV- ond OBS-file!
> Three days later (without altering anything) I tried again, recorded receiver-ubx-data and tried to translate with tecq. In both cases I used the latest version of teqc.
>
> teqc +nav rinex_n.txt data.ubx > rinex_o.txt
>
> But now I only receive the OBS-file, the NAV-File will be generated but with 0 K.
> I tried on different computers under Windows and OSX with the same poor result. teqc produces (amongst others) the following warnings which my be responsible:
>
> Notice ! NAVSTAR GPS SV G10 in 'data2.ubx': ToC 2020 Jan  9 18:00:00.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G12 in 'data2.ubx': ToC 2020 Jan  9 17:59:44.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G14 in 'data2.ubx': ToC 2020 Jan  9 18:00:00.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G15 in 'data2.ubx': ToC 2020 Jan  9 16:00:00.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G17 in 'data2.ubx': ToC 2020 Jan  9 18:00:00.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G19 in 'data2.ubx': ToC 2020 Jan  9 18:00:00.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G24 in 'data2.ubx': ToC 2020 Jan  9 17:59:44.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G25 in 'data2.ubx': ToC 2020 Jan  9 18:00:00.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G29 in 'data2.ubx': ToC 2020 Jan  9 17:59:44.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
> ! Notice ! NAVSTAR GPS SV G32 in 'data2.ubx': ToC 2020 Jan  9 18:00:00.000 not in 2020 Jan 16 16:55:20.000 to 6075 Dec 31 23:59:59.999 by +/- 140 min
>
> I do not understand why teqc assumes the date of Jan 9, because the ubx-file was recorded Jan 16 (the same GPS-week 2088 as Jan 12!)
> On my Windows-PC I found older versions of teqc from 2013, 2015 and 2016. All those versions do the desired job and produce OBS- and NAV-files.
>
> My students use Windows-PC and Mac, so I am dependant on the proper working of the availabe version of teqc.
> Perhaps it's not an issue of teqc, but I always used the same receiver and I record its data always the same way with u-center and I've already tried different versions of u-center.
>
> Having no more ideas, I dare to ask you...
> Thanks in advance for your time and ideas
>
> Best regards
>
> Helmut
>
> Dr. Helmut Albrecht
> 0170 3221107
> Vorstandsvorsitzender
> Luftsportring Aalen e.V.
> Hinteres Härtle 6
> Flugplatz Elchingen
> 73450 Neresheim
> 07367/7122
> edpa at lsr-aalen.de
> www.lsr-aalen.de
> Eingetragen im Vereinsregister
> des Amtsgerichts Ulm VR 500126
>
>

-- 
Dr François Meyer  Tel : (+33) 3 81 66 69 27   Mob : (+33) 6 27 28 56 83
Dir. exécutif plateforme OscIMP
Dir. LNE-LTFB, laboratoire temps-fréquence associé au LNE
Institut UTINAM / OSU Theta
41b avenue de l'Observatoire, BP1615
25010 Besancon cedex - FRANCE
** Universite de Franche-Comte ** CNRS UMR 6213 ** UMS 3245


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