During last long lock, there's high coherence right in the bucket with PRCL and REFL_A_RF45 both I and Q. Not much coherence with MICH, some with SRCL.
https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_lho_1236519918/
This coherence might not see high, but at 50 Hz it projects into DARM at 1e-20 m/rHz, whereas DARM is 4e-20 m/rHz. That's about a 5% contribution in amplitude to DARM.
Just added a new feature to BruCo:
if the --range=xxx option is added, then BruCo multiplies the PSD of the target signal by the coefficient xxx (0.00025=1/4000 to convert CAL-DELTAL_EXTERNAL to strain) an compute the BNS range, for the target signal and the estimated coherence subtraction. So one can get a ballpark idea of how much that noise contributes to the range.
For example, removing the coherence with PRCL would bring the range from 100.23 to 102.95 Mpc (the absolute calibration might be a bit off since I'm using a old calibration curve for CAL-DELTAL_EXTERNAL)
This is really fantastic!