[teqc] helpful tip of week 1924

Lou Estey lou at unavco.org
Wed Nov 23 08:16:44 MST 2016


This week's tip: the qc '-w' option

The '-w' option can be used to alter the width of the qc ASCII time plot:

[3949] teqc +help | grep width
          -w[idth] #        set time width of qc ASCII timeplot to 0 < # <= 255 (default = 72)

If you use teqc's quality check (qc) functionality, then you are familiar with the first
part of the output showing, in a rough graphical way, the qc analysis of each SV.  The "width"
of this plot is the number of columns of qc analysis for each SV, which by default is 72.
(Why 72?  Back in the Microsoft DOS days, output on that system was limited to 80 printable
ASCII characters per line, so labeling each SV line used 4 characters at its front and 4 characters
at its end, leaving a maximum of 72 left over, which is a reasonably convenient number because
if qc-ing 24-hours worth of data then each of the 72 columns represents 20 minutes of data.)

So, if you want, the number of qc analysis columns can be adjusted from 1 to current maximum of 255.
(The code could easily be changed to allow more than 255, but so far no one has ever asked for that.)

Why might you want to change the width from default value?  Let's look at an example.  Here is a
24-hour case where there are some interesting alignments of ionospheric and clock slips:

[3991] teqc +quiet +qcq tmp.02o
version: teqc  2016Nov7

  SV+---------|--------|--------|--------|--------|--------|--------|--------+ SV
  27|m_                          __--------__               _---oMooCoomooCoo| 27
  10|moomL                __----mL1-_                          _--ooCoomooCoo| 10
  17|m1.L_               _----oomooMooCo1-L_                          _---Coo| 17
  15|-L,-L_                _---omooMooCoom;L_                          __--mo| 15
   8|moomL_                         __-------__                __--oCoomooCoo|  8
  23|moomooILL_              __---oMooCLLL_                         __---oCoo| 23
  28|moomooILL_                           _----CooMo,-_               _--oCoo| 28
  26|IoomooIooC;LL                  ___---___                        _---oCoo| 26
  18|--omooIooC,LL              __---oCoomoomLL_                           _-| 18
  29|---mooIooCooCooIL_                _--------__                          _| 29
   9|---mooIooCooCooIooCL                     _______                       _|  9
   7| _---oIooCooCLL_                          _----omooCooCo^L_             |  7
  21| __----ooCo2CL_              __---oomoomooCoLL_                         | 21
   5|    _--ooCooCooIooCooIoL_                        ______                 |  5
  30|       _--ooCooIooCooIoom;^L                       ______               | 30
  14|       _---oCoomooCo1-L              __---CooMoom1L_                    | 14
   4|          __---Io2C-__                         __--CooCooMoomooC2L      |  4
   6|            _---ooCooIoomoomoo-L_                        ___----__      |  6
  25|             _---oCooIoomoomo^L               __---CooCLLL_             | 25
  24|            __---oCooI,LL_                          _---oCooIooCoom^L_  | 24
  22|                   __---moomooIooCoomLL                 __-----___      | 22
   2|                      __----------------__               __----CoL-__   |  2
   3|_                       __--ooIooCoomoomooC2L_                    ______|  3
  31|-___                         _---CoomoomooCooI1+L                   ___-| 31
  11|     ______                        _----ooCooIoomooCooCL                | 11
  20|             ________                   __--oIoomooCooCooIo2L_          | 20
   1|                   __-------__                _--ooCooCooIooIooCL_      |  1
  13|                      __-----__                  _--ooCooCooIooCoomLL   | 13
-dn|121  1 ++1 ++ 1 + ++  213443111332334333211+ 1 + 1      ++ 1232+++1++1  |-dn
+dn|c32c12c 2c1 c13c2 c1 c34c56c32c44c44c55c33c11c1 c22c 1c1 c13c43c 2c42c12|+dn
+10|aabb99999999879998876889aacbaa9aabcccba988877766677778877679aaa97899888a|+10
Pos|oooo                                                                    |Pos
Clk|-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++|Clk
    +---------|--------|--------|--------|--------|--------|--------|--------+
00:00:00.010                                                        23:59:45.010
2002 Apr 10                                                          2002 Apr 10
...
       first epoch    last epoch    hrs   dt  #expt  #have   %   mp1   mp2 o/slps
SUM 02  4 10 00:00 02  4 10 23:59 23.17  15  47557  34307  72  0.82  0.78    220

Using the global time windowing options '-st' and '-e' (see tip of week 1919), we can
zoom-in on the first of the ionospheric slip alignments which takes place in the third hour
of data.  Using '-w 60', we can also have each qc analysis column correspond to 1 minute
of data so that in this case each column now corresponds to exactly 4 data epochs
(and here specifying '-st' and '-e' only to the hour:minute:second; see the third pointer
in tip of week 1919):

[3993] teqc -w 60 +quiet -st 02:00:00 -e 02:59:45 +qcq tmp.02o
version: teqc  2016Nov7

  SV+|---------|---------|---------|---------|---------|---------+ SV
  23|-ooo----,,Ioooooooooooooooooooooooo;+^^LLLLLLLLLLLL_________| 23
  26|-ooo---Iooooooooooooooooooooooooooooooooooooooooooooooooooo-| 26
  28|-ooo----,,Iooooooooooooooooooooooo;;L,LLLLLLLLLLLLL_________| 28
  18|-ooo----Ioooooooooooooooooooooooooooooooooooooooooooooooooo-| 18
   9|-ooo---Iooooooooooooooooooooooooooooooooooooooooooooooooooo-|  9
  29|-ooo----Ioooooooooooooooooooooooooooooooooooooooooooooooooo-| 29
   7|-ooo----Ioooooooooooooooooooooooooooooooooooooooooooooooooo-|  7
  21|----------Loooooooooooooooooooooooooooooooooooooooooooooooo-| 21
   5|----------,Looooooooooooooooooooooooooooooooooooooooooooooo-|  5
  30|                         _________________________----------| 30
  14|                            __________________________------| 14
  11|____________________________________________________________| 11
-dn|2222ccc22                           +++++++++++++++111122222|-dn
+dn|c222cccc22                           +++++++++++++111122222c|+dn
+10|999999999999999999999999999999999999988888888887778888999999|+10
Pos|oooo   oooooooooooooooooooooooooooooooooooooooooooo         |Pos
Clk|^  +^^^-+     +    +     +    +     +    +     +     +    +^|Clk
    +|---------|---------|---------|---------|---------|---------+
02:00:00.000                                            02:59:45.000
2002 Apr 10                                              2002 Apr 10
...
       first epoch    last epoch    hrs   dt  #expt  #have   %   mp1   mp2 o/slps
SUM 02  4 10 02:00 02  4 10 02:59 .9417  15   2004   1743  87  0.62  0.65    249
SWN 02  4 10 02:00 02  4 10 02:59 1.000  15   2022   1743  86  0.62  0.65    249

Now we can clearly see that the receiver stopped tracking all SVs for 3 or more minutes,
but that reacquiring dual-frequency tracking on the SVs did not occur at the same time;
indeed, reacquiring both L1 and L2 tracking is spread out over another 3 minutes.

Zooming-in even more so that now there is one epoch per qc analysis column:

[3994] teqc -w 80 +quiet -st 02:00:00 -e 02:19:45 +qcq tmp.02o
version: teqc  2016Nov7

  SV+--------------------|-------------------|-------------------|-------------------+ SV
  23|oooooooooooooooo ------------,,,,,,,,,,,,,Ioooooooooooooooooooooooooooooooooooo-| 23
  26|oooooooooooooooo ------------,,Iooooooooooooooooooooooooooooooooooooooooooooooo-| 26
  28|oooooooooooo-ooo ------------,,,,,,,,,,,,,Ioooooooooooooooooooooooooooooooooooo-| 28
  18|oooooooooooo-ooo ------------,,,,Iooooooooooooooooooooooooooooooooooooooooooooo-| 18
   9|oooooooooooooooo ------------,,Iooooooooooooooooooooooooooooooooooooooooooooooo-|  9
  29|oooooooooooo-ooo ------------,,,Ioooooooooooooooooooooooooooooooooooooooooooooo-| 29
   7|oooooooooooo-ooo ------------,,,,,,Iooooooooooooooooooooooooooooooooooooooooooo-|  7
  21|---------------- ---------------------L,oooLooooooooooooooooooooooooooooooooooo-| 21
   5|---------------- ----------------------L,oooLoooooooooooooooooooooooooooooooooo-|  5
  30|            -                                                                   | 30
  14|            -                                                                   | 14
   4|            -                                                                   |  4
  11|________________ _______________________________________________________________| 11
  13|            _                                                                   | 13
-dn|2222222222222222ccccccccccccc2222222221                                        c|-dn
+dn|2222222222222222ccccccccccccc2222222221                                        c|+dn
+10|9999999999999999 99999999999999999999999999999999999999999999999999999999999999 |+10
Pos|oooooooooooooooo             oo|Pos
Clk|             +   ^^^^^^^^^^^^-     +                     +                     ^|Clk
    +--------------------|-------------------|-------------------|-------------------+
02:00:00.000                                                                02:19:45.000
2002 Apr 10                                                                  2002 Apr 10
...
       first epoch    last epoch    hrs   dt  #expt  #have   %   mp1   mp2 o/slps
SUM 02  4 10 02:00 02  4 10 02:19 .2750  15    702    496  71  0.57  0.66     71
SWN 02  4 10 02:00 02  4 10 02:19 .3333  15    720    496  69  0.57  0.66     71

Now it is really clear that after the tracking break that 7 SV first started tracking the
pseudorange CA at the same epoch, but that L1 and L2 phase tracking resumed at different
times.  The other two SVs also started tracking with a 'loss-of-lock' indicator being
logged by the receiver.  (You may want to review the symbol table by running `teqc ++sym`.)
Compare this zoomed-in qc analysis view with what was seen with the 24-hour view at the start.

So the '-w' option along with time windowing can often allow you to quickly get at details of
what was happening with a problematic receiver or other problematic data, right down to an
epoch by epoch level.

(The astute observer will also note that in this last qc run we've uncovered a slight formatting
bug on the 'Pos' line!  Ah, well, as Roseanne Roseannadanna said, "It's always something ...")

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
week 1906: the '+v[erify]' option - http://postal.unavco.org/pipermail/teqc/2016/002128.html
week 1907: '+C2', '+L5', "+L6', '+L7', '+L8', and '+all' options - http://postal.unavco.org/pipermail/teqc/2016/002130.html
week 1908: no doppler shortcut; RINEX L2 - http://postal.unavco.org/pipermail/teqc/2016/002131.html
week 1909: using paths w/ file names - http://postal.unavco.org/pipermail/teqc/2016/002132.html
week 1910: the (un)importance of file names - http://postal.unavco.org/pipermail/teqc/2016/002133.html
week 1911: notices, warnings, and errors - http://postal.unavco.org/pipermail/teqc/2016/002134.html
week 1912: the '-max_rx_SVs' option - http://postal.unavco.org/pipermail/teqc/2016/002137.html
week 1913: the end of '++igs' and '+igs' - http://postal.unavco.org/pipermail/teqc/2016/002140.html
week 1914: splicing together RINEX files - http://postal.unavco.org/pipermail/teqc/2016/002144.html
week 1915: using '-O.int' and '-O.dec' - http://postal.unavco.org/pipermail/teqc/2016/002145.html
week 1916: '+doy' option - http://postal.unavco.org/pipermail/teqc/2016/002146.html
week 1917: '-tbin' and '-ast' options - http://postal.unavco.org/pipermail/teqc/2016/002152.html
week 1918: mp12 RMS before/after Oct 2013 - http://postal.unavco.org/pipermail/teqc/2016/002158.html
week 1919: the global windowing options - http://postal.unavco.org/pipermail/teqc/2016/002159.html
week 1920: '-M.dec' and '-N.dec' options - http://postal.unavco.org/pipermail/teqc/2016/002163.html
week 1921: combining time filtering options - http://postal.unavco.org/pipermail/teqc/2016/002176.html
week 1922: helping me (or someone else on the list) help you - http://postal.unavco.org/pipermail/teqc/2016/002187.html
week 1923: the "build" line - http://postal.unavco.org/pipermail/teqc/2016/002190.html




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