[teqc] helpful tip of week 1906

Lou Estey lou at unavco.org
Wed Jul 20 12:36:29 MDT 2016


This week's tip: the +v[erify] option

This is another option that you probably have never used, but it's been around almost
from the beginning of teqc.  From teqc's on-line help:

[833] teqc +help | grep verify
          +v[erify]            verify conformance to input format standard to stdout

It might sound complicated, but the functionality is quite simple.  With '+v',
teqc is reading the input -- whatever it might be as long as it is all of one
format type -- using whatever other options you supply, but simply not converting
into the input to RINEX, BINEX, etc.  If a problem is encountered, teqc will report
that problem to stderr (as usual), and if the problem is something that cannot be
resolved (i.e. the problem requires some human intervention or the data after that
point is lost), then teqc exits.  If teqc gets all the way through, through then teqc
reports that fact with a message to stdout on a file-by-file basis (or one message
if the input is stdin).

An example with a Trimble .tgd file from a NetR9:

[839] teqc +v 5024K68287201507190000a.tgd
? Error ? translation may have started with GPS week 1906 rather than 1854
          (try using '-week 1854' option)
! Notice ! incomplete code for parsing Trimble .dat record 32 (Galileo ion/UTC model) in file '5024K68287201507190000a.tgd' ... skipping
teqc: '5024K68287201507190000a.tgd' readable as Trimble .dat format

... or you could also apply the '+quiet' option to suppress all notices and warnings
(and the one questionable error, in this case):

[840] teqc +quiet +v 5024K68287201507190000a.tgd
teqc: '5024K68287201507190000a.tgd' readable as Trimble .dat format

(Note for those of you familiar with Trimble data: teqc makes no distinction between
a Trimble .dat file and a .tgd file. The main difference is that a .dat file contains
a record 17 per epoch for GPS+SBAS data and a .tgd file contains a record 27 per epoch
for full GNSS data plus a few other GNSS related records.  Structure-wise in a file,
it's the same thing.)

Ok, those of you familiar with messages from teqc will say, "hey, I get messages
like that notice and the annoying thing about the GPS week even without using '+v',
like when I'm trying to create RINEX."  And you're right.  This is a way to get at
many potential "reading" problems with your input, even using options like '-O.dec'
for decimation, or changing observables, or SV or constellation filtering, etc.
All of those take effect.  You're just skipping the whole "create RINEX" part.

You might ask what's the difference between using '+v' to read the input, vs.
'+meta' or '+mds', which are also file-by-file.  The answer is that the metadata
extraction options, '+meta' and '+mds', do not read everything.  These options
are after metadata and time of epochs.  So, going back to Trimble's records 17
or 27, with '+meta' and '+mds' once the time of the data epoch is established,
the flow of teqc moves on without trying to figure out the observed constellation
and observables.  With the '+v' option, all is read unless time windowing excludes
epochs.  (Most filtering, except for time windowing, takes place after records 17
or 27 are read.  Same design for other formats.)

Here's an example where there are multiple files of RINEX: observation (.obs)
and various navigation files for different constellations (.gps, .glo, .sbs):

[1004] teqc +quiet +v tmp.*
teqc: 'tmp.glo' readable as RINEX V.2.10 format
teqc: 'tmp.gps' readable as RINEX V.2.10 format
teqc: 'tmp.obs' readable as RINEX V.2.11 format
teqc: 'tmp.sbs' readable as RINEX V.2.11 format

The basic idea is to help find problems with the input without the clutter of converting
to RINEX or BINEX.

(I may consider trying to get '+v' to work with files of different formats all in
one command line, but no guarantees for the future.)

Happy teqc-ing!

cheers,
--lou

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Louis H. Estey, Ph.D.              office:  [+001] 303-381-7456
UNAVCO, 6350 Nautilus Drive           FAX:  [+001] 303-381-7451
Boulder, CO  80301-5554            e-mail:  lou  unavco.org
      WWW:  http://www.unavco.org   http://jules.unavco.org

"If the universe is the answer, what is the question?"
                                                -- Leon Lederman
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Past helpful tips:

week 1894: using teqc config files - http://postal.unavco.org/pipermail/teqc/2016/002067.html
week 1895: qc of high-rate data - http://postal.unavco.org/pipermail/teqc/2016/002071.html
week 1896: UNIX/Linux shells for Windows - http://postal.unavco.org/pipermail/teqc/2016/002072.html
week 1897: '-' vs. '+' teqc options - http://postal.unavco.org/pipermail/teqc/2016/002076.html
week 1898: auto-identification of formats - http://postal.unavco.org/pipermail/teqc/2016/002092.html
week 1899: auto-identification vs. format flags - http://postal.unavco.org/pipermail/teqc/2016/002096.html
week 1900: square brackets in options - http://postal.unavco.org/pipermail/teqc/2016/002105.html
week 1901: using option '+mds' - http://postal.unavco.org/pipermail/teqc/2016/002108.html
week 1902: qc results w/ problematic nav messages - http://postal.unavco.org/pipermail/teqc/2016/002113.html
week 1903: '-no_orb[it]' and '-no_pos[ition]' options - http://postal.unavco.org/pipermail/teqc/2016/002115.html
week 1904: '-week' option - http://postal.unavco.org/pipermail/teqc/2016/002117.html
week 1905: using '+bcf' for XYZ/geodetic conversion - http://postal.unavco.org/pipermail/teqc/2016/002126.html





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