J. Kissel, F. Matichard, P.Fristchel

After putting together information from all over the everywhere, I've produced (dare I call it) a NoiseBudget for the H2 OAT Y Arm cavity. Attached are the results. 
[[Editorial Note: I've uploaded -v2 of the plots. Now the calibration for the cavity length signal is just 1e-9 [m/nm], as Matt suggests in his comments below. Also removed the free-running laser frequency noise from SARM L budget since it's not applicable when the PLL is on, and corrected the ylabel typo on the Pitch estimate, so it now reads [rad/rtHz] as expected.]]

All data was measured starting at 2012-07-17 04:50UTC (7 averages, BW 0.005, 50% overlap), which we believe is the second stretch of cavity lock shown in LHO aLOG 3463.

Captions (labeled by page number):

(1) The Money Plot, showing the my predicted cavity length against the directly measured cavity length, in [m/rtHz]
(2) A similar model of the cavity pitch, but still a prediction without a measurement that directly confirms it

[[The remaining plots are merely for support of the first two:]]
(3 - 5) For ITMY, individual NoiseBudget breakdown of test mass motion degree of freedom used in the model (L, V, and P)
(6 - 8) For ETMY, individual NoiseBudget breakdown of test mass motion degree of freedom used in the model (L, V, and P)
(9) A comparison between the BSC-ISI's input spectra for Y (projected to L in the model), and RX (projected to P in the model)
(10 - 11) For ITMY and ETMY respectively, the contribution of every degree of freedom input to pitch of the test mass
(12 - 13) Directly measured spectra of BSC8- and BSC6-ISI's ST2 GS-13s,
(14 - 15) Model transer function between all DOFs at the SUS point and the test mass.


Calibration Details:

ISI ST2 GS13s
     - Channels: H2:ISI-$(OPTIC)_ST2_DAMP_$(DOF)_IN1_DQ
     - Input filter calibration: ON (creates an ideal 1 Hz geophone, that asymptotes to 1 [(nm/s) / ct] at high frequency)
     - DTT: (Based on LHO aLOG 3458)
         units: [m]
         gain: 1.59e-10 [m/ct] (1e-9 [m/nm] * 1/(2pi) [rad / (rad/s)])
         poles: 0,0,0
         zeros: 0.7 0.7
         (I gathered/plotted/calibrated the data in DTT for sanity check, then exported the data, uncalibrated, to Matlab)
     - Matlab:
         Used production calibration file:
         $(SeiSVN)/seismic/BSC-ISI/Common/Calibration_BSC_ISI/aLIGO/aLIGO_BSC_ISI_Calibration.mat
         code snippet:
              isiCalibration = load(bscCalibFile);
              gs13Model_nm = abs(squeeze(freqresp(isiCalibration.GS13_Model,2*pi*freq)));
              rawData = load(bscDataFile);
              rawFreq = rawData(:,1);
              for  iChan = 2:size(rawData,2)
                  interpData(iChan,:) = interp1(rawFreq,rawData(:,iChan),freq);
              end 

              for iDOF = 1:6
                  % X Y RZ Z RX RY
                  bscData(1).ST2.CART(iDOF,:) = interpData(iDOF+1,:) ./ abs(gs13Model_nm' * 1e9);
                  bscData(2).ST2.CART(iDOF,:) = interpData(iDOF+7,:) ./ abs(gs13Model_nm' * 1e9);
              end 

Cavity Length Signal 
     - Channel: H2:SUS-ETMY_M0_LOCK_L_IN1_DQ (which is the control signal from the VCO FMON [[I think]], but passed directly to the M0 TOP stage of the QUAD)
     - DTT: (Based on LHO aLOG 3482)
         units: [m]
         gain: 1e-9 [m/nm]
         poles: (none)
         zeros: (none)
     - Matlab: (Based on above)
         code snippet:
              % H2:SUS-ETMY_M0_LOCK_L_IN1_DAQ is already calibrated into [nm], so we just
              % need to multiply by 1e-9 [m/nm]
              cavityData = interpData(14,:) .* 1e-9; % [m] 


Data collection details:

The original data collection .xml can be found here:
$(SusSVN)/sus/trunk/Common/Data/2012-07-17_H2OAT_ASDs.xml

which has been exported to 
$(SusSVN)/sus/trunk/Common/Data/2012-07-17_H2OAT_ASDs.txt


Model script: $(SusSVN)/sus/trunk/QUAD/Common/MatlabTools/plotsinglearmmotion.m