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Entry  Fri Dec 7 19:24:43 2012, Den, Ayaka, Update, SUS, oplevs as acoustic and seismic noise couplers at high frequencies IMG_0111.JPGIMG_0112.JPGETMY_olreso_copy.pngYARM.png
    Reply  Fri Dec 7 20:34:31 2012, Ayaka, Update, SUS, oplevs as acoustic and seismic noise couplers at high frequencies YARM_acous_oplev.pdf
Message ID: 7799     Entry time: Fri Dec 7 20:34:31 2012     In reply to: 7798
Author: Ayaka 
Type: Update 
Category: SUS 
Subject: oplevs as acoustic and seismic noise couplers at high frequencies 

I will just leave the picture of spectrum that shows the injected acoustic sound effects due to the oplevs.

 YARM_acous_oplev.pdf

red line: POY error without oplev feedback nor acoustic noise
blue line: POY error without oplev feedback but with acoustic noise
brown line: POY error with oplev feedback but without acoustic noise
green line: POY error with oplev and acoustic noise

You can see there is noise only at green line around 70 - 100 Hz. And it does not look like the acoustic signal is injected directly to the arms but the acoustic sound couples to the original noise source.

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