Today I performed a standard set of noise injections on the DARM, MICH and PRCL degrees of freedom; the OLTFs are reported in Figures 1 to 3, in Figure 4 there is the longitudinal noise budget, which shows that neither MICH or PRCL are limiting but for some contribution to the noise coming from the 50 Hz and harmonics.

In any case, I also used the noise injections to compute a new Alpha filter; despite the predicted new suppression being quite good (e.g. in Figure 5), no change was observed in the DARM spectrum at all;  it is possible that the 1/f^3 noise is hiding this effect, but the new filter has been added (ommented) to the MICH Subtraction configuration file.