I measured Transfer Functions of vertical DoF(SF GAS, BF GAS, BF V, IM V) of PR3, and found SF GAS is strange. From below figure we can know there exists only one peak. Unforutunately I cannot find the previous TF of SF GAS of PR3 (I can only find the one at May 2017) because I don't know the place of folder, but I can find TF of IM V measured in May 2018. At that time, V DoF seemed to be good, and so I measured trend data of GAS(2018 5~now). Figure shows the value of SF GAS is not changed from May at which TF was good. I'm not sure whether this is because SF is touched at something or not.

By the way, I also noticed the drift of YAW in the morning. It drifts about 400 urad in 30 min at around 9. The above measurement is held in the condition with this drift, and it could affect the result.