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Entry  Mon Mar 10 21:14:58 2014, ericq, Summary, LSC, Composite Error Signal for ARms (3) model.pngsimSweep.pdfalsSweep.pdf
    Reply  Wed Mar 26 11:16:59 2014, ericq, Summary, LSC, Composite Error Signal for ARms (3) simlink.pdfsimulatedCESARLock.pdf
Message ID: 9710     Entry time: Mon Mar 10 21:14:58 2014     Reply to this: 9751
Author: ericq 
Type: Summary 
Category: LSC 
Subject: Composite Error Signal for ARms (3) 

Using Koji's mathematica notebook, and Nic's python work, I set out to run a time domain simulation of the error signal, with band-limited white noise added in. 

model.png

Basically, I sweep the displacement of the cavity (with no noise), and pass it to the analytical formulae with the coefficients Koji used, with some noise added in. I also included some 1/0 protection for the linearized PDH signal. I ran a sweep, and then compared it to an ALS sweep that Jenne ran on Monday; reconstructing what the CESAR signal would have looked like in the sweep. 

The noise amounts were totally made up. 

They matched up very well, qualitatively! [Since the real sweep was done by a (relatively) noisy ALS, the lower noise of the real pdh signal was obscured.]

simSweep.pdfalsSweep.pdf

Given this good match, we were motivated to start trying to implement it on Monday. 

At this point, since we've gotten it working on the actual IFO, I don't plan on doing much more with this simulation right now, but it may come in handy in the future...

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