In a similar way to how the PRC gain is computed using the phase camera, I computed the dark port transfer function of the carrier using the B1p phase camera data.

I used 10 mins of the single bounce data during the OMC calibration as Pref and looked at 10mins of data after 1 hour of science mode (Pscience). The dark port transfer function for the carrier is then: TF = Pscience/Pref*Tprm*Tbs*Rinput*Tbs*Tsrm

Using the values from the OptChar page:

Tprm = 0.04835; Tsrm = 0.396; Tbs = 0.5; Rinput = 1-0.01377;

The dark port transfer function is shown after 1 hour of science run is shown in figure 1.

Using the input power (17 W), we can estimate the carrier power in the dark port, shown in figure 2. On average, after 1 hour of science mode the carrier power at the dark port was 0.0884 W, versus 0.1034 at the start of science mode.

We can apply the same logic to the B1p and B1s photodiodes to confirm whether they give similar results to those obtained with the phase camera.

In order to better compare, we can use the phase camera and also compute the sidebands dark port transfer function and calibrate their power at the dark port. The sum carrier + sidebands should give a similar value to the one given by the B1p and B1s photodiodes.

Figure 1. shows the calibrated phase camera powers (carrier and sidebands) after 1 hour of science mode (30th April).

Figure 2. shows a comparison of the phase camera calibrated power vs the calibrated B1p and B1s photodiode signals. For comparison the carrier only power and carrier + sbs signals are shown. The carrier + sbs power seems in agreement with the B1p PD2 and B1s PD1 photodiodes (B1p PD1 had weird results, maybe because of the shutter being on at some point).

Analysis of the OMC scans might show if the relative power between carrier and sidebands matches that seen by the phase camera.