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Entry  Thu Feb 13 00:25:36 2020, Duo, DailyProgress, , Noisemon at L1 L1DACNoise.zipplot.pdf
    Reply  Wed Mar 11 12:46:20 2020, rana, Computing, Noise Budget, Noisemon at L1 
       Reply  Sat Apr 18 16:21:32 2020, Duo, Computing, Noise Budget, Noisemon:DAC noise analysis from L1 and H1 noisebudget.pdfdiagram.pdfDACnoise-comparison.pdf
          Reply  Mon Apr 20 22:56:30 2020, rana, DailyProgress, Noise Budget, Noisemon:DAC noise analysis from L1 and H1 DACnoise-comparison.pdfdacNB.zip
Message ID: 1850     Entry time: Mon Apr 20 22:56:30 2020     In reply to: 1849
Author: rana 
Type: DailyProgress 
Category: Noise Budget 
Subject: Noisemon:DAC noise analysis from L1 and H1 

for some reason the DAC noise estimate is too high, it can't really be so large compared to the real DARM curve (see the noise budget curves from LLO - there are other noise sources besides DAC noise)

some possibilities:

  1. maybe the DAC noise calibration into meters is wrong? I can't tell from the code where this came from. It would be good to put a comment in there.
  2. perhaps most of this noise is actually angular noise. The ASC control signals are adjusted by tuning the digital coefficients (before MASTER_OUT) so that the angle to length coupling is minimized. I think something like this has to be done to remove the angular noise from the DAC noise estimate.
  3. internal saturation of the DAC noise monitor?

I hve modified the code to plot nicer and also to remove some divide by zero problems. There is also still some warnings about other divide by zero - those should probably be fixed by examining how better to handle it when the coherence goes to zero.

Attachment 1: DACnoise-comparison.pdf  78 kB  Uploaded Mon Apr 20 23:56:38 2020  | Hide | Hide all
Attachment 2: dacNB.zip  21.454 MB  Uploaded Tue Apr 21 00:08:10 2020
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