J. Kissel

I've finally gotten around to creating a transfer function measurement script that can compare all OPOS transfer function results, assuming they've been exported and processed by 
    /ligo/svncommon/SusSVN/sus/trunk/OPOS/Common/MatlabTools/plotOPOS_dtttfs_M1.m
and that comparison script is called
    /ligo/svncommon/SusSVN/sus/trunk/OPOS/Common/MatlabTools/plotallopos_tfs.m

With this new analysis infrastructure, I've exported the best L1 SUS OPO data from LHO aLOG 37508, which now lives in,
    /ligo/svncommon/SusSVN/sus/trunk/OPOS/L1/OPO/SAGM1/Data
        2018-01-29_0900_L1SUSOPO_M1_WhiteNoise_L_0p01to500Hz_tf.txt
        2018-01-29_0900_L1SUSOPO_M1_WhiteNoise_P_0p01to500Hz_tf.txt
        2018-01-29_0900_L1SUSOPO_M1_WhiteNoise_R_0p01to500Hz_tf.txt
        2018-01-29_0900_L1SUSOPO_M1_WhiteNoise_T_0p01to500Hz_tf.txt
        2018-01-29_0900_L1SUSOPO_M1_WhiteNoise_V_0p01to500Hz_tf.txt
        2018-01-29_0900_L1SUSOPO_M1_WhiteNoise_Y_0p01to500Hz_tf.txt
and processed it with the above mentioned script. Sadly -- the LLO results are confusing on their own because they require a different calibration depending on whether DOFs are translation or rotation, and those calibrations don't correspond to any physical meaning as far as I can tell. I've merely scaled the DC gain of the TF to match the model (independently for translation and rotation, but the same number within each). This implies that the gain has something to do with the OSEM to Euler basis change -- and from what I've recently discovered with Alvaro, it might be a simple case of incorrect units in the rotation lever arm. I'll discuss this with Stuart and Alvaro to see if we can come up with a physical explanation.

So -- take LLO's data matching the model's [m/N] and [rad/N.m] with a deer-sized salt lick.

That being said, I'm then able to plot H1 and L1's results; see alloposs_2018-03-12_H1SUSOPO_Phase3a_ALL_ZOOMED_TFs.pdf.

Several things are immediately obvious:
   - R2R and P2P are measured to be almost identical, but don't match the model very well.
   - The L2L primary resonances are identical and match the model well.
   - L1's V2V transfer function shows two primary resonances, where H1's only shows one. Both show cross-coupling to yaw, but the L1 results show *very* substantial cross-coupling to what appears to be the Yaw resonance, where as H1's only shows minor coupling.
   - The nastiness we've been worried about in H1's Y2Y transfer function seems to match the L1 data, except for one cross-coupled pitch mode at 1.65 Hz.

I'm not sure if this tells us too much in the hunt for what's wrong with the H1 suspension, but it certainly provides a lot of good food for thought.

P.S. I spent a good bit of time this evening making sure everything committed to the SusSVN is now under the OPOS directory instead of the VOPO directory. This includes data from LLO. So please svn up your local copy ASAP, and begin filling out the directory structure that now conforms to the rest of the SUS repository.