As a preliminary check, DC offsets were applied to the ETMX pitch and yaw setpoints. Corresponding changes were observed in the QPD signals. The response was more visible in the Y channel, while the X channel response was less clear in the time-series data.
Representative spectra and time-series data are attached.
I intentionally changed the Pcal-X beam position by moving the pico motors and checked the response in the QPD signals.
(ETMX was in the LOCK_ACQUISITION state during this work.)
TCam images were taken before and after the pico-motor movement.
A detailed analysis of the QPD response will be performed later.