Here is a summary of the brute force coherence report already posted in a previous comment to an elog entry describing the good sensitivity lock of last Friday.

Basically, there is no large coherence anywhere, except for the well known periscope peaks that are coherent with ISS signals, IMC angular signals and PSL periscope (figure 1-3)

At low frequency, there is coherence with SUS-ETMY_L3_ESDAMON_?? signals. This was not there in the past, so I guess this coherence is just due to a change in the control strategy. If I'm not mistaken, this signal is just a monitor of the correction sent to the ESD, so coherence with DARM is normal. Please correct me if wrong... (figure 4)

In the 10-30 Hz there is coherence with ASC-MICH_P (figure 5)

In the 10-70 Hz region one dominant source of noise is longitudinal control, since there is coherence with MICH and SRCL (figures 6-7). This noise is not dominant and still a factor of few from the measured sensitivity.

In the higher frequency region (above 100 Hz), there is coherence with ISS and PSL periscope as already pointed out, but there is also some coherence with AS signal: ASC-AS_A/B_DC_SUM, ASC-AS_A_RF36_I_PIT/YAW etc... Together with the main jitter peaks, there is a broadband noise floor at about 1e-10 m/rHz from 100 to 1000 Hz. This might be intensity noise or noise in high order modes that is not completely filtered by the OMC (figure 8).

Finally, a 90 Hz bump seems to be coherent with HAM5 signals (figure 9)