I looked into the glitches created by Robert's dust injections. In brief: some of the glitches, but not all of them, look very similar to the loud glitches we are hunting down
Here is the procedure:
- select all drops of the range in the two hours of injection
- for each one, load three minutes of data, compute the 30-300 Hz BLRMS and find the glitch tims as the maximum of the BLRMS peaks
In this way I could detect a total of 42 glitches. The last plot shows the time of each glitch (circles) compared with the time of Robert's taps (horizontal lines). They match quite well, so we can confidently conclude that all the 41 glitches are due to dust. The times of my detected glitches are reported in the attached text file, together with a rough classification (see below)
I then looked at all the glitches, one by one, to classify them based on the shape. My goal was to see if they are similar to the glitches we've been hunting.
A few of them (4) are not clear (class 0), some others (14) are somehow slower than what we are looking for (class 3). Seven of them have a shape very close to the loud glitches we are looking for (class 1), and 16 more are less obvious but they could still be of the same kind, just larger (class 2).
See the attached plots for some examples of classes.
It seems the text file of glitch times didn't make it into the attachments, would you mind trying to attach it again?
Ops! Here's the file with the glitch times.
Gabriele, Did you check which of Robert's glitches caused any ADC/DAC adjurations? The glitch shape will start changing significantly once the amplitude is big enough to start saturations. PS: The ODC master channel has a bit that will toggle to red (0) is any of the subsystems reports a saturation (with 16k resolution) - it might be exactly what you need in this case.
Stefan, I checked for some ADC and DAC overflows during this data segment. The OMC DCPDs ADCs overflowed during several of these. There were still some with SNRs of 10,000 that didn't overflow like this. The segments are pasted below. They're a bit conservative because I'm using a 16 Hz channel without great timing. There were no ADC overflows in POP_A, and no DAC overflows in the L2 or L3 of the ETMs. I didn't check anything else. This is not quite the same as what the ODC does, which is a little more stringent. I'm just looking for changes in the FEC OVERFLOW_ACC channels.
1123084682.4375 1123084682.5625
1123084957.3750 1123084957.5000
1123086187.3750 1123086187.5000
1123086446.8125 1123086447.3750
1123088113.0625 1123088113.1875
1123088757.4375 1123088757.6250
1123088787.1875 1123088787.3125
1123088832.3125 1123088832.4375
1123089252.6250 1123089252.7500
1123089497.2500 1123089497.3750