I have identified a new 2nd order violin mode at 998.017Hz as being on ITMX.    I used Patrick's program to create damping filters for it at 998.02Hz. This mode is best damped when the phase is set to 270 degrees on the ITMX yaw, with gain=50. This is now in the filter bank as ITMX mode 19. This violin mode has been reduced by 2 orders of magnitude.

I have also identified a new 2nd order violin mode at 997.613Hz as being on ITMY.    I created a damping filter for it at 997.62Hz, which functions best when the phase is 270 degrees on the ITMY yaw, with gain=20. This is now in the filter bank as ITMY mode 19. This violin mode was reduced by about 1.5 orders of magnitude.

I have adjusted Patrick's pre-existing ITMX mode 13 filter from 998.09Hz to 998.08Hz to better address the violin mode, which at higher resolution is located at 998.083.  Even though this is only 0.04Hz away from the next lowest frequency mode, their filters are sufficiently narrow so as not to interfere with each other.  This violin mode was reduced by 3 orders of magnitude.

I have adjusted the gain for ITMY mode 16 (997.78Hz), from gain=200 to gain=20.  Today, this was sufficient to damp the mode by over 2 orders of magnitude.

These changes have not yet been permanently committed to the guardian.  This will happen after we watch these settings through the full acquisition of lock.  

violinmodes_1.png shows these peaks before and after these damping filters were applied.