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Entry  Mon Feb 28 10:58:13 2011, Frank, Notes, NoiseBudget, Seismometer installed 
    Reply  Tue Mar 1 08:43:06 2011, rana, Notes, NoiseBudget, Seismometer installed 
       Reply  Tue Mar 1 11:32:35 2011, Frank, Notes, NoiseBudget, Seismometer installed 
Message ID: 522     Entry time: Tue Mar 1 08:43:06 2011     In reply to: 519     Reply to this: 523
Author: rana 
Type: Notes 
Category: NoiseBudget 
Subject: Seismometer installed 

The fringe wrapping signal comes from the velocity difference between the table and the cavity. You can calculate the spectrum of this by propagating the seismometer spectrum through the single pendulum approximation for the cavity.

For the feedback, you only have to suppress the seismometer signal. Since the fringe wrapping is nonlinear, its not predicted by the transfer function method.

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