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Entry  Wed Feb 12 19:47:40 2014, Jenne, Update, LSC, Calibrated REFL signals CalibratedUsingPRMdrive.pdf
    Reply  Wed Feb 12 20:30:41 2014, Koji, Update, LSC, Calibrated REFL signals 
Message ID: 9631     Entry time: Wed Feb 12 20:30:41 2014     In reply to: 9630
Author: Koji 
Type: Update 
Category: LSC 
Subject: Calibrated REFL signals 

We usually want to remove PRCL from the Q quadrature for each PD.
Therefore, you are not supposed to see any PRCL in Q assuming the tuning of the demod phases are perfect.
Of curse we are not perfect but close to this regime. Namely, the PRCL in Qs are JUNK.

In the condition where MICH is supressed by the servo, it is difficult to make all of the Qs line up because of the above PRCL junk.
But you shook MICH at a certain freq and the signal in each Q signal was calibrated such that the peak has the same height.
So the calibration should give you a correct sensing matrix.

If you tune the demod phases precisely and use less integrations for MICH, you might be able to see the residual MICH lines up on the Q plot.

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