J. Kissel

We're continuing to struggle to even get back to DRMI locking as of last night (LHO aLOG 30614). One suspicion is the sharp feature 27.0977 Hz (using a 0.005 Hz BW ASD) that has suddenly appeared, as shown in Jenne's attached ASD. 

Because we haven't yet measured them, and we're dead in the water until we figure out the problem, I've taken the time to excite and measure all of the HAM2 and HAM3 HSTS and HLTS's highest vertical mode frequencies, modeled to be at 27.3 Hz and 28.1 Hz, respectively. The results are as follows:

 Optic      Sus. Type     V3 Mode Freq (Hz)
  MC1         HSTS            27.387
  MC2         HSTS            27.742
  MC3         HSTS            27.426

  PRM         HSTS            27.594
  PR2         HSTS            27.414

  PR3         HLTS            28.211

None match up with the mystery line. The closest is MC1, at ~0.3 Hz away.

All values were measured with 5 averages at 0.005 Hz BW. I attach screenshots of the DTT and awggui templates for MC3 as an example. The DTT templates have been copied and committed into the Sus repository here:
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/Common/2016-10-18_H1SUSPR3_V3_Mode.xml
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC1/Common/2016-10-18_H1SUSMC1_V3_Mode.xml
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC2/Common/2016-10-18_H1SUSMC2_V3_Mode.xml
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC3/Common/2016-10-18_H1SUSMC3_V3_Mode.xml
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/Common/2016-10-18_H1SUSPR2_V3_Mode.xml
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/Common/2016-10-18_H1SUSPRM_V3_Mode.xml