stefan.ballmer@LIGO.ORG - posted 22:45, Wednesday 07 November 2018 - last comment - 12:20, Friday 09 November 2018(45110)
LSC MICH and SRCL FF redone
Craig, Peter, Stefan We remeasured and turned on the MICH and SRCL feed-forward. In particular, we - Moved all violin notches to the MICH and SRCL filter banks - Moved the AC coupling to 0.1Hz (in FM2 of MICHFF and SRCLFF1 FM2) so its phase influence is small. - Moved all feed-back top the ETMX. - remeasured the transfer functions and fitted the filters (in FM3 of MICHFF and SRCLFF1 FM3). - Updated Guardian to engage them. Attached are the MICH and SRCL OUT to DARM transfer function with and without the feed forward engaged. For MICH we get about x100 suppression, for SRCL about x50.
Images attached to this report
Comments related to this report
MICH FF comparison from O2 (dark blue), this morning (cyan), and now (red).
Images attached to this comment
the linear term is much reduced, but what is the magnitude of the bilinear term relative to the linear term? 1/10 ?