Robert, Chris, Sheila

Chris and Jamie got the script that records the psl camera centroids working on the gaurdian machine, it generates epics channels H1:PSL-FSS_TRANS_CENTROID_PIT, H1:PSL-FSS_TRANS_CENTROID_YAW, H1:PSL-PMC_TRANS_CENTROID_PIT, H1:PSL-PMC_TRANS_CENTROID_YAW with the position of the centroids in pixels.  For now the script is in userapps/isc/h1/scripts/AnalogCameras.

You need to give it the username and password for the cameras when you call the script.

For the ref cav trans, pitch has not really moved since Nov 22 (when chris first got this script running) (pit is  119, yaw is 177)  https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=8707

So, it seems like this position has been fairly stable.  the ref cav alignment always drifts up (meaning that the beam is high compared to the cavity position based on the refl camera), so if this was due to the cavity moving we would have seen some difference in the trans centroid position.  It seems like the beam moving, not the cavity. 

With Robert we looked at the long term drift, which doesn't seem to be correlated with temperature.  (the 20 minute fluctuations are). 
In the last several weeks we have had two times when the transmitted power was stable for several day stretches, both of those were times when the transmitted power was 1.2V.  (perhaps we need to realign the AOM and the cavity periscope each time we realign to get the power that high). 

I've attached a trend of the ref cav trans PD and the threshold over a long period of time.  It seems like this has never been stable, but the resonant threshold was set to be much lower than the normal value for most of the time since the PSL came online.

It may be that no one has cared about the stability of the reference cavity transmitted power until we started using it for ALS.