J. Kissel

After tuning up an excitation with color that roughly matches the shape of the quiescent HAM2 and HAM3 displacement, I drove ISI HAM2 and ISI HAM3 in X as a calibration run for H1SPIH23. I'll process and post the results and conclusions tomorrow. 

MEASUREMENT CONFIG NOTES:
Input Mode Cleaner was LOCKED, but no IFO.

The SPI 
   - QPDs were well centered, with their latest calibration installed. Their normalized spot positions remained well below 0.1 [V/V] throughout the excitation. QPDA's dark noise is still terrible; that hasn't yet been resolved. QPDB should be functioning as normal.
   - MEAS and REF IFOs had their nominal contrast of ~75% and 100% respectively, and they remained as such all throughout the excitation.
   - phase unwrapper algo was reset prior to each measurement run to be sure.

HAM ISIs were isolated the entire time, with sensor correction ON. HAM3 was using the CRS in RY.
Blend configurations are screenshotted and attached.

All Suspensions in HAM2 and HAM3 were DAMPED and aligned. PR3 had its Estimators L, P, and Y ON.

(big big 6.something EQ at 11:23 UTC in Alaska / Alutians)
Reference Time  2026-09-03 17:09:49 UTC 
HAM2 excitation 2026-09-03 18:34:14 UTC - 18:58:09 UTC
HAM3 excitation 2026-09-03 18:59:31 UTC - 19:23:26 UTC

Excitation parameters and frequency dependence attached in the screenshots.
Used the same exact excitation for both platforms.
excitation bandwidth was from 0.005 to 200 Hz, but I rolled off the excitation band at either end with a 5th order elliptic with corners at 0.01 and 50 Hz.
Frequency resolution was therefore 0.005 Hz.
Took 10 avgs.

Corner station Sensor correction mode was WINDY during the HAM2 excitation.
Interestingly? Sadly? there was an 5.3 mag Alaskan earthquake in the middle of the HAM3 excitation (started at 18:59:31 UTC). That automatically changed the corner station sensor correction configuration to CONFIG_EQ at 19:05:17 UTC, then back to CONFIG_WINDY at 19:15:18 UTC.

The typical total RMS of each ISI X motion during the the excitation was ~1e-6 [m]_RMS. 

DTT Templates and results are saved to the following DTT templates
   /ligo/svncommon/SeiSVN/seismic/Common/SPI/Data
       2026-09-03_170949UTC_H1SPIH23_DIFF_DISP_ASD.xml
       2026-09-03_183414UTC_H1SPIH23_DIFF_DISP_ASD_HAM2Drive_X.xml
       2026-09-03_185931UTC_H1SPIH23_DIFF_DISP_ASD_HAM3Drive_X.xml