[teqc] Curing files with GPS rolllover issues

François Meyer fmeyer at obs-besancon.fr
Fri Apr 12 12:50:34 UTC 2019


We have an issue concerning the same family of receivers (Ashtech Z12-T, 
time dedicated receiver) ; observation files look ok but navigation
files have 0 length ; we circumvent the problem by using nav files from 
other receivers but a fix would still be most welcome.

Typical command line used :

teqc -ash r -week 2048 -O.obs C1+L1+L2+P1+P2 +smoothing
  +obs BSNC0990.19O
  +nav BSNC0990.19N
  +st 190409000000.00 +dd 1 RBSNCA19.098 RBSNCA19.099 RBSNCA19.100

error messages (may or may not be related to the issue) :
! Notice ! 'RBSNCA19.098': reversing msec phase adjustment upon rx msec clock reset ...
! Alert ! 'RBSNCA19.099': change of receiver number from '___' to '' ~ 2019 Apr  8 03:30:00.000
! Alert ! 'RBSNCA19.099': change of antenna number from '___' to '' ~ 2019 Apr  8 03:30:00.000
! Alert ! 'RBSNCA19.100': change of receiver number from '___' to '' ~ 2019 Apr  9 03:30:00.000
! Alert ! 'RBSNCA19.100': change of antenna number from '___' to '' ~ 2019 Apr  9 03:30:00.000

resulting nav file (0 size) :

-rw-rw-r-- 1 user group      0 april 10 03:36 BSNC1000.19N

[user at pluton ashtech_raw]$ /raid0/z12t/prog/teqc -version
executable:  /raid0/z12t/prog/teqc
version:     teqc  2019Feb25
build:       Linux 2.4.20-8|x86|gcc|Linux 32|=+
[user at pluton ashtech_raw]$

Incriminated raw files are available here for testing :

http://perso.utinam.cnrs.fr/~fmeyer/z12bogus/

Best regards,

On Thu, 11 Apr 2019, Joe Evjen wrote:

> FYI only, passing along a possible fix for GPS-week-rollover-affected GPS data files.
> 
> A user of https://geodesy.noaa.gov/OPUS/ reported collecting a post-rollover data file on an old
> ashtech receiver which looked normal, except all time tags were 1024 weeks off, in August 1999. Using
> teqc
> 
> "with: Teqc -week 2048 B_T3_A99.235 > RT310980.19o Original as downloaded B file > output file. That
> generated a rinex file with the correct date. The file appears to be a typical rinex file. However
> opus returns “...opus doesn’t recognize format...”


-- 
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


More information about the teqc mailing list