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Entry  Fri Jan 30 02:57:03 2015, Jenne, Update, Modern Control, First try with PRCL ASC Wiener filtering 9x
    Reply  Tue Mar 31 22:27:43 2015, Jenne, Update, Modern Control, Preliminary PRMI angular Wiener results PRMI_31Mar2015.pdf
       Reply  Sat Apr 4 17:54:03 2015, rana, Update, Modern Control, Preliminary PRMI angular Wiener results 
       Reply  Tue Apr 21 01:17:13 2015, Jenne, Update, Modern Control, T-240 self-noise propagated through stack and pendulum T240selfnoise.pngLimits.tar.gz
Message ID: 11202     Entry time: Sat Apr 4 17:54:03 2015     In reply to: 11186
Author: rana 
Type: Update 
Category: Modern Control 
Subject: Preliminary PRMI angular Wiener results 

This is a very cool result. I'm surprised that it can work so good. Please post what frequency dependent weighting you used on the target before running the Wiener code.

I think its important to tune it to keep the low frequencies from getting amplified by a factor of 10 (as they are in your plots). The seismometers are all just noise acting like thermometers and tilt sensors below 0.1 Hz. Temperature and tilt do not couple to our interferometer very much.

It also seems weird that you would need 20th order filters to make it work good. In any case, you can always split the SOS up into pieces before making the digital filters. For LLO, we used 3 buttons in some cases.

Quote:

Before locking for the evening, I wanted to try again implementing the Wiener filters that I had designed back in Jaunary (elog 10959). 

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