I. Clustered Inspiral Triggers
The following pairs of plots show the triggers
from the two segments that are common to the sets of (i) clustered Inspiral
triggers obtained using 100 Hz high pass filter, and (ii) triggers produced
by PTmon using a 70 - 300 Hz bandpass filter. The primary purpose
of producing the plots was to learn the necesary techiques. The upper
plots show the triggers produced by the inspiral template bank as blue
asterisks, replaced by red asterisks if they are coincident with the monitor
triggers (over a wide interval because of the clustering). The lower
plots show POB_Q triggers as blue plus signs, and AS_Q triggers as green
crosses. The first two plots shows coincident POB_Q triggers circled
in red when they are coincident, and the other plots show AS_Q triggers
circled in red when they are coincident. It appears that the POB_Q
triggers are all used during the part of the segment that was processed
through the inspiral code, and are coincident with 42% and 47% of the inspiral
triggers for the segments labelled as #10 and #108 respectively.
71% of the inspiral triggers in segment #10 are coincident with AS_Q triggers.
Notes on AS_Q
Additional monitor triggers are expected because
(i) some of the inspiral template triggers are vetoed using a chi-squared
veto, and (ii) AS_Q has been found to have a lot of glitches around 70
Hz that would be removed by going to a 100 Hz high pass filter. Inspiral
triggers will be missed if they are loud at high frequencies.
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II. Unclustered Inspiral Triggers
The next plots compare the PTmon POB_Q triggers
for the same segments with the unclustered Inspiral triggers, again produced
using 100 Hz high pass filter. The first two plots use a -4/+8 s
coincidence window and the third plot shows the second segment using a
-1/+6 s window. The -4/+8 window picks up 34% of inspiral triggers
in the first segment, and 40% in the second. The -1/+6 window picks
up 34% of the inspiral triggers in the second. Deadtimes were calculated
for the second segment, since this doesn't have along gap in inspiral triggers.
These are 43% and 32% respectively, which are unacceptably high.
However, inspection of the estimated frequencies of the POB_Q triggers
shows that approximately two thirds are well below a low frequency cut-off
of 100 Hz. These include the group of unused triggers between 350
and 400 Hz. A reduced dead time of around 10% would be more reasonable.
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REFL_Q Triggers
The next plot compares the inspiral triggers
for the second segment with PTmon REFL_Q triggers having snr at least 15.
Using a coincidence window of -3/+4 s to allow
for the scatter of inspiral triggers around the time of an AS_Q glitch,
34% of inspiral triggers are coincident with 68% of the REFL_Q triggers,
with a dead time of 26%. Using a slightly smaller window of -3/+3
reduces the dead time of 23% with only one less inspiral trigger caught.
Raising the low frequency cut-off for REFL_Q would remove a few triggers,
but it is probably not possible to make the window much smaller.
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The second plot, which covers the time of the second inspiral trigger
'stripe' around 300 s and is bandpassed 100-300 Hz, illustrates the
reality of the AS_Q/REFL_Q connection, and also shows that the loudest
AS_Q glitch in a disturbance will not necessarily correspond to the loudest
glitch on an auxiliary channel.