This afternoon I measured the spectra and the transfer functions of the mirror installed on in the PR tank (to be used as a part of the injection telescope of the filter cavity).

The mirror motion in pich and yaw is sensed by means of a optical lever. The spectrum of the motion in the two degree of freedom is shown in fig1 and 2 of the attached file.

In order to measure the transfer functions, I injected white noise in pitch and yaw (with an amplitude of 3 V ).  To improve the diagonalization of the sensing, I changed the the sensing matrix appying a rotation of 0.04 rad. I have also slightly changed the driving matrix, to reduce the excitation of the yaw resonance when injecting noise on pitch. The comparison between the TFs before and after these changes are shown in fig 3-4 and 5-6 for yaw and pitch respectively.