I ran a BruCo scan for LHO. The full report is available here:

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_lho_1128339017/

Here is my excerpt:

• In the 10-20 Hz region the largest coherence is with DHARD_P (fig 1)
• MICH/SRCL coherence is 4-10 times below the sensitivity at low frequency, so no worrysome yet (unless the coupling is non stationary, to be investigated). Fig. 2 and 3
• PRCL is lower than the other LSC loops (fig. 4)
• The PSL periscope is a win as usual. The largest coherence is in the region 304-368 Hz, but there is a bit of lower coherence in many other bands: 150-155 / 175-185  / 202 / 240-260 / 280-290 / 551-555 / 615-623 Hz (fig. 5)
• I see coherence with OMC-LSC_DITHER_OUT at few frequencies: 80 / 96 / 128 / 288 Hz, not sure what this means
• There is coherence with PEM-EY_MAG_EBAY_SEIRACK at 281.5 Hz and 283.5 Hz.
• Above 500 Hz I can see low coherence with PEM-EY_MAG_EBAY_SUSRACK (fig. 6). This is rather small, but being an environmental channel it might be important to investigate it further.

Beside these, there are few more puzzling coherences at higher frequencies:

• 453 Hz ASC-REFL_A_RF9_I_YAW and RF45

• 485 Hz ASC-REFL_A_RF9_I_PIT and RF45 / ISI-HAM2_BLND_GS13RY_IN1_DQ

• 991.5 - 996 Hz / 1004.5 Hz ASC-OMC_A/B_SUM_OUT

• 1954.5 Hz OMC-LSC_I_OUT

• 2449.0 Hz / 2458.5 Hz LSC-PRCL_OUT

• In the region between 3300 Hz and 3400 Hz SRCL gets to quite high coherence

• 3619 Hz PRCL / SRCL / LSC-REFL_SERVO_CTRL_OUT / LSC-MCL_IN1/OUT