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Entry  Mon Mar 22 15:01:24 2010, Dmass, Laser, ISS, ISS Spectra ISSILandOL.pdfGreenPDsBudget.pngIRPDsBudget.pngPDSubtracAll.pdf
    Reply  Tue Mar 23 15:01:29 2010, Dmass, Laser, ISS, ISS Spectra SubtractTestCoh.pdfSubtractTest.pdf
       Reply  Tue Mar 23 17:05:11 2010, Dmass, Laser, ISS, ISS Spectra 
          Reply  Tue Mar 23 21:24:57 2010, Dmass, Laser, ISS, ISS Spectra 
             Reply  Wed Mar 24 00:09:39 2010, Dmass, Laser, ISS, ISS Spectra 
                Reply  Wed Mar 24 22:12:49 2010, Mott, Laser, ISS, fb0 error 
                   Reply  Fri Mar 26 17:05:43 2010, Mott, Laser, ISS, fb0 error 
                      Reply  Tue Mar 30 16:44:20 2010, Mott, Laser, ISS, fb0 error 
                         Reply  Fri Apr 9 11:35:56 2010, Mott, Laser, ISS, fb0 error 
    Reply  Thu Mar 25 02:06:53 2010, Dmass, Laser, ISS, ISS Spectra 
       Reply  Thu Mar 25 02:38:54 2010, Koji, Laser, ISS, ISS Spectra 
          Reply  Thu Mar 25 10:38:24 2010, mevans, Laser, ISS, ISS Spectra 
          Reply  Thu Mar 25 13:29:18 2010, Dmass, Laser, ISS, ISS Spectra 
             Reply  Thu Mar 25 14:16:32 2010, Dmass, Laser, ISS, MZ Spectra! rawdata.zipLockedPhaseNoise.pdf
Message ID: 699     Entry time: Tue Mar 23 17:05:11 2010     In reply to: 698     Reply to this: 701
Author: Dmass 
Type: Laser 
Category: ISS 
Subject: ISS Spectra 

Quote:

On Hartmut's suggestion, I have tested my subtraction algorithm.

  • I took the raw spectra of on of the IR PDs (PD3).
  • I generated two white time series via MATLAB's "rand" function at a level of several below the "signal floor" of this spectrum
  • I added this to the PD3 time series to generate the
  • I subtracted one noisy time series from the other.
  • I recovered the subtraction I expect from the noise levels, and this is consistent with the predicted subtraction based on the coherence

I have shorted the green PDs together after the transimpedance amplifier, and the IR PDs together before the buffer I made (after the ISS PD box). I will check if the problem is upstream of the ADC next, since the subtraction works. Hopefully I find some electronics shenanigans, and won't be able to subtract the two identical PD spectra

 Currently waiting for FB0 to successfully restart, so far it has said it failed to mount something, then read "Kernel Panic..." and not gotten farther. This seems not good.

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