Evan, Stefan

Using a line at 6409.7Hz we found a null in the frequency noise coupling. Thus we took the REFL_9 to OMC_DCPD_A transfer function (plot 1).
This is a nice modelling challenge - thus we spend some time calibrating it in meaningful units.

Calibration:
 - OMC_DCPD_9 (H1:IOP-LSC0_MADC0_TP_CH12):
   - This is just a copy of the filters in the PDA filter module, plus the 13.7kHz 17.8kHz poles from preamp (alog 17647). We did not take into account the AA board, but it should be the same for both channels:
   - G=8.63151e-07
   - P=0.87, 7.689, 7.689
   - Z=10.07, 78.912, 90.642, 13700, 17800
 - REFL9 (H1:IOP-LSC0_MADC1_TP_CH28):
   - The gain is 2900V/WattsRF (see alog 10661) x (12dB whitening) x 1638.4cts/V, plus a z=1,p=10Hz whitening filter (again, no AA board compensation)
   - G=5.2867e-08 = 1/(2900*3.9811*1683.4)
   - P=1
   - Z=10

Plot 2 shows the 9 OMC_DCPD traces during heating, calibrated in A/rtHz

The xml template is in LIGO-T1500414
https://dcc.ligo.org/T1500414