## Unwrapping and calibrating (closure) phases

If we plot TriplePhaseC (since we haven't calibrated the phases yet,
TriplePhaseC is identical to the uncalibrated TriplePhase) of the calibrator
vs Time, we notice large jumps which are phase wraps rather than bad data.
Therefore, we have to unwrap the calibrator phase data first. Use the
"All in 1"
option to replot this data into one graph, and then use
Calibrate|Visibility|Triple|ManualUnwrap to define a window around the group
of data points which you want wrapped to the other side. Enter "+1" when asked
to provide the direction of the wrap, if you have, like in the following figure,
chosen to move the negative phase data into the positive half. The plot below shows
the situation after unwrapping.

Now add back our program star to the
star plot selection, and change the
data variable
in the calibration widget to "TriplePhase". Click on "Calibrate", and the log should
read like the following. Notice that the first three channels do not contain any
data since one or more baselines are bad for this triple. Also, channel 11 has the
metrology laser straylight in it, so it was flagged too by the script.

*
Warning(CALCOEFFS): no valid data points found! OB= 1, Bl= 1, Ch= 1*

Warning(CALCOEFFS): no valid data points found! OB= 1, Bl= 1, Ch= 2

Warning(CALCOEFFS): no valid data points found! OB= 1, Bl= 1, Ch= 3

Solution calculated for TR= 1, Ch= 4. (RMS [d] = 3.413)

Solution calculated for TR= 1, Ch= 5. (RMS [d] = 3.812)

Solution calculated for TR= 1, Ch= 6. (RMS [d] = 4.045)

Solution calculated for TR= 1, Ch= 7. (RMS [d] = 3.811)

Solution calculated for TR= 1, Ch= 8. (RMS [d] = 3.962)

Solution calculated for TR= 1, Ch= 9. (RMS [d] = 3.886)

Solution calculated for TR= 1, Ch= 10. (RMS [d] = 4.087)

Warning(CALCOEFFS): no valid data points found! OB= 1, Bl= 1, Ch=11

Solution calculated for TR= 1, Ch= 12. (RMS [d] = 5.089)

Solution calculated for TR= 1, Ch= 13. (RMS [d] = 5.771)

Solution calculated for TR= 1, Ch= 14. (RMS [d] = 4.164)

Solution calculated for TR= 1, Ch= 15. (RMS [d] = 4.166)

Solution calculated for TR= 1, Ch= 16. (RMS [d] = 5.787)

Solution calculated for TR= 1, Ch= 17. (RMS [d] = 4.489)

Solution calculated for TR= 1, Ch= 18. (RMS [d] = 4.885)

Solution calculated for TR= 1, Ch= 19. (RMS [d] = 6.110)

Solution calculated for TR= 1, Ch= 20. (RMS [d] = 5.349)

Calibration applied for stars FKV0497 FKV0509 .

These are the data after calibration (and un-selecting the "All in 1" option
for plotting). Of course, the binary phases are
all over the place, but the calibrator is close to where it should be.

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