evan.hall@LIGO.ORG - posted 08:35, Tuesday 19 January 2016 - last comment - 08:40, Tuesday 19 January 2016(25019)
MICH and SRCL coupling into DARM, FF on versus FF off
Related: 25010
I wanted to see how well the LSC feedforward performs from 10 to 600 Hz.
I injected noise into MICH (and then SRCL) twice: once with the FF on and once with the FF off.
In both cases, the FF improves the coupling in the bucket, but makes it worse elsewhere. We already knew this was true around a few hertz (22586), but it seems to also be true above 500 Hz or so.
The intrinsic couplings (no FF) seem to have an uptick approaching 1000 Hz.
Non-image files attached to this report
Comments related to this report
Looking both at BruCo reports and my yesterday noise injections, it looks like it's possible and necessary to improve the feedforward at low frequency, while the high frequency part is not very important.