[teqc] SUM line bug if repeated data epochs

Lou Estey lou at unavco.org
Thu Mar 5 09:21:24 MST 2009


All,

A few days ago I discovered a bug on teqc's qc SUM line when
there are repeated data epochs.  For example, taking a 1-hour
file of 30-second data and duplicating each of the first 20
data epochs, e.g.:

  09  3  3  0  0  0.0000000
  09  3  3  0  0  0.0000000
  09  3  3  0  0 30.0000000
  09  3  3  0  0 30.0000000
  09  3  3  0  1  0.0000000
  09  3  3  0  1  0.0000000
  09  3  3  0  1 30.0000000
  09  3  3  0  1 30.0000000
...

the qc full of this data for the current version of teqc
will appear as:

[1577] teqc +dm 59.5 +qcq dup.obs
...
Poss. # of obs epochs   :    120
Epochs w/ observations  :    140
...
       first epoch    last epoch    hrs   dt  #expt  #have   %   mp1   mp2 o/slps
SUM 09  3  3 00:00 09  3  3 00:59 1.167  30    985    985 100  0.43  0.37    985
SWN 09  3  3 00:00 09  3  3 00:59 1.000  30    985    985 100  0.43  0.37    985

Note that the alternate summary line SWN has the correct span of 1 hour,
but the original summary line SUM has a span of 1.167 hour = 140/120.

This was easy to fix, and the fixed teqc yields:

[1578] teqc +dm 59.5 +qcq dup.obs
...
Poss. # of obs epochs   :    120
Epochs w/ observations  :    120
Epochs repeated         :     20  (16.67%)
...
       first epoch    last epoch    hrs   dt  #expt  #have   %   mp1   mp2 o/slps
SUM 09  3  3 00:00 09  3  3 00:59 1.000  30    985    985 100  0.43  0.37    985
SWN 09  3  3 00:00 09  3  3 00:59 1.000  30    985    985 100  0.43  0.37    985

You'll notice that there is also now a new line reporting
duplicated data epochs.  (This does _not_ necessarily
mean that the GNSS observables are duplicated; the only
info being checked is that this is a data epoch -- e.g. not
a comment epoch -- and that the time tag of the epoch
is identical to the previous epoch.)  For the ideal
situation (firmware + translator), the "Epochs repeated"
should always be 0.

This change will be in the next release, which if all
goes well will be next week.

cheers,
--lou


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