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Entry  Fri Jan 15 12:04:26 2010, Sanjit, mevans, Update, Adaptive Filtering, Canceling noise again! OAF_15JAN2010.png
    Reply  Tue Jan 26 19:51:44 2010, Sanjit, rana, Update, Adaptive Filtering, OAF details C1ASS_TOP.pngC1SUS_SRM_XYCOM1.pngUntitled.png
       Reply  Mon Feb 1 18:31:00 2010, Sanjit, Update, Adaptive Filtering, OAF details 
          Reply  Mon Feb 1 21:51:12 2010, Sanjit, Update, Adaptive Filtering, OAF details 
       Reply  Fri Feb 5 00:52:55 2010, Sanjit, Update, Adaptive Filtering, OAF at 0.1-1.0 Hz OAF_04FEB2010_noOAF.pngOAF_04FEB2010.png
          Reply  Fri Feb 5 01:04:58 2010, Sanjit, Update, Adaptive Filtering, OAF at > 5Hz OAF_04FEB2010_highFreq.png
             Reply  Sat Feb 6 00:10:08 2010, Sanjit, Update, Adaptive Filtering, OAF at > 5Hz 
Message ID: 2557     Entry time: Mon Feb 1 21:51:12 2010     In reply to: 2555
Author: Sanjit 
Type: Update 
Category: Adaptive Filtering 
Subject: OAF details 

 I tried some combination of PEM channels and filters to improve OAF performance at other frequencies, where we do not have any improvement so far. There is progress, but still no success.

Here are the main things I tried:

For the ACC channels replaced the 0.1 Hz high pass filters by 3Hz high pass and turned off the 1: filter.

Then I tried to incorporate the Z ACC/GUR channels, with some reasonable combination of the others.

The Z axis Guralp and Accelerometers were making OAF unstable, so I put a 0.1 gain in all four of those.

Following the PEM  noise curves Rana has put up, we should probably use

  • two ACC_Y channels (3:0, Notch24, AA32)
  • two GUR_Z channels (filters: 0.1:0, 1:, AA32, gain 0,1)
  • one RANGER_Y, just because it works (0.1:0, 1:, Notch24, AA32)

In the end I tried this combination, it was stable after I reduced the GUR_Z gain, but looked very similar to what we got before, no improvement at 5Hz or 0.5Hz. But there was a stable hint of better performance at > 40Hz.

Possibly we need to increase the GUR_Z gain (but not 1) and try to use ACC_Z channels also. Since we can not handle many channels, possibly using one GUR_Z and one ACC_Z would be worth checking.

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