Summary:  PRMI and DRMI and locking with reasonable stability.  BS top mass damping rings more than we'd like, and it seems like we should swtich out oplev damping for M3 wit damping. 

• Aligned PRMI adjusting BS and by hand in MICH dark, PRM by hand with PRX. This gives PRMI flashes up to 60 counts on POPAIR 18 I DQ
• there was a bug in the guardian that meant oplev damping wasn't actually coming on for PRMI acquisition, I fixed this and added a line to turn it off after PRMI locked. 
• PRMI is stably locked
• DRMI locked easily on the first try, when optical lever damping was not on.  The build ups were semi stable, the main fluctuation seemed to be correlated with BS M3 pit. THen I could not lock DRMI with the optical lever damping on for 10 minutes, and it relocked once I turned oplev damping off.  
• Looked at a time series of the optical lever and M3 wits while PRMI was trying to acquire.  It seems that M3 Wits have a better SNR than the optical lever for the motion when trying to acquire.  
• I moved the BS sliders by 10 urad in pitch and yaw.  Screenshot attached. 
  • The step response has significant ringing in at 0.4 Hz, where the overshoot is about half the step size.  We should be able to improve this with the top mass damping.   
  • The optical lever is badly cross coupled, as has been noted before.  
  • Based on the table below I applied a calibration of 6.4 to oplev pit and 4 to oplev yaw to match the optical lever steps to the M3 wit steps in my dtt template.  The pitch spectra comparison shows that M3 wit agrees with the optical lever, but has better SNR.  The yaw optical lever shows significantly more motion than M3 wit, but this is probably from the cross coupled pitch signal (see coherences).  

• DRMI locking was stable for 10 minutes, it took a few minutes to relock after the lockloss.  I'm stopping DRMI work for now so Keita can do his test.