Elenna, Gabriele

We retuned the MICH and SRCL feedforward. This time we injected MICH and SRCL noise with the LSC FF on, and measured the residual coupling. We then used that residual as a correction for the running FF filter, and refit the result. In this way we could improve the SRCL feedforwad by up to 10 dB. We did not see a consistent improvement over all frequencies with the new MICH, so we reverted to the old filter. In any case MICH had little coherence with DARM, so we're ok.

The attached plots show the coupling of MICH and SRCL to DARM without FF (blue), with the old feedforward (green) and with the new (red).

All changes are in the guardian