Ibrahim, Oli
We ran a long overnight Bounce measurement on the BBSS. The BRDs weren't installed for this measurement. AOSEM flags were not installed, and we were 100g heavier at M1 than we are now (this measurements was taken before 90294).
With those settings in mind, our measurements show that our Bounce mode was at 19.80Hz. The last time these measurements were taken, back in the staging building (88141), the bounce mode with no BRDs was ~19.74Hz, so they're consistant.
The measurement file can be found in /ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/Common/Data/ 2026-05-19_2200_H1SUSBS_M1M2_BounceNoBRD_V_0p001to40Hz.xml as r13012.
Attached here is a zoomed in version of this file. The mode is indeed clearly visible in M2 UL, and the frequency is known well enough for proper BRD tuning. Thanks!
The Q of the mode seems to be about 3400. Maybe a higher excitation would be possible to get a better definition. Were you at the saturation limit to drive M1 V?
