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Entry  Wed Jun 3 17:04:08 2015, ericq, Update, PEM, Wilcoxon Accelerometer Huddle Test AccHuddle.jpg
    Reply  Wed Jun 10 02:50:39 2015, ericq, Update, PEM, Wilcoxon Accelerometer Huddle Test hats2Acc.png3hatcode.zip
       Reply  Mon Jun 15 16:55:39 2015, ericq, Update, PEM, Accelerometers installed MC2.jpgMC1.jpgmc2accspectra.png
          Reply  Wed Jun 17 15:31:50 2015, ericq, Update, PEM, Accelerometers fully installed IMCcoherence_Jun172015.xml.zipIMCcoherence.png
       Reply  Sun Jul 5 18:14:13 2015, Ignacio, Update, PEM, Wilcoxon Accelerometer Huddle Test 8x
    Reply  Sun Jun 21 13:21:03 2015, rana, Update, PEM, Wilcoxon Accelerometer Huddle Test 
Message ID: 11362     Entry time: Wed Jun 17 15:31:50 2015     In reply to: 11359
Author: ericq 
Type: Update 
Category: PEM 
Subject: Accelerometers fully installed 

MC1 accelerometer has been plugged in. The modecleaner locking has been intermittent today, but I looked at a 15 minute lock in DTT, looking at the STS1 seismometer and both accelerometer triplets. Plot and DTT xml attached.

For the sake of not cluttering up everything with legends, the coherence plots are organized by direction (x, y, z), and include the coherence of each of the three sensors (sts, acc1, acc2) with the IMC control signal and the IMC transmitted RIN. 

Some remarks:

  • The 1 Hz pendulum motion is about equal amounts of X and Y, which makes sense, as MC1 and 3 are at an angle
  • The ~3 Hz stack motion seems to be entirely in the X direction. Why?
  • The bounce/roll bands are strongly coherent with Z motion at MC2. 
  • The STS does not appear to have any low frequency advantage over the accelerometers, in terms of coherence, contrary to what I would expect even without a thermal enclosure. 
  • The control signal and RIN RMSs are clearly dominated by noise in the 1-3Hz band, where we have reasonable coherence. Good prospects for noise subtraction...

Attachment 1: IMCcoherence_Jun172015.xml.zip  234 kB
Attachment 2: IMCcoherence.png  538 kB  Uploaded Wed Jun 17 16:35:24 2015  | Hide | Hide all
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