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Entry  Tue Oct 25 20:04:40 2011, Mirko, Update, Adaptive Filtering, Adaptive filter witness and EP SNR MC-F_SNR_to_Dark_noise.pngCoherence.png
    Reply  Tue Oct 25 21:49:13 2011, Den, Update, Adaptive Filtering, Adaptive filter witness and EP SNR gur1_x.jpggur1_y.jpggur1_z.jpg
    Reply  Tue Nov 1 18:16:50 2011, Den, Update, Adaptive Filtering, Adaptive filter witness and EP SNR translation_length.jpgtrans_tilt.jpgseismic_length.jpgfiltering.jpgtilt_filtering.jpg
Message ID: 5740     Entry time: Tue Oct 25 21:49:13 2011     In reply to: 5738
Author: Den 
Type: Update 
Category: Adaptive Filtering 
Subject: Adaptive filter witness and EP SNR 

Quote

Coherence of seismometers to MCL:


STS1 is located at the vertex. x-axis along the x arm.
GUR1 is located at the IMC MC2 mirror. Same orientation.
Coherence.png

=> 1. Only the x-direction has good coherence (to be expected)
     2. Only good coherence at 1.5-4Hz (huh?)

So probably other noise sources are dominating. Let's look into noise projections. Remember IMC autoalignment is off.

A quick adaptive filter run with only the GUR1 and STS1 witnesses applied only to MCL didn't really do anything. Some more thought needs to be invested into the AA and shaping filters.

Indeed, only GUR1_X is reasonable. Static Wiener filtering (length = 2500) of MCL with witness channels GUR_1_X, GUR_1_Y, GUR_1_Z proves your measurements.

We need to callibrate seimometers. I think that now we see velocity, not displacement. It might be useful to amplify the seimometer singal before ADC to make sure that our signal is not ADC noise.

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