NAOJ GW Elog Logbook 3.2
Yuhang, Eleonora
Some measurement on the local control noise was done, in order to compare their performamces to those of AA.
This is for the input mirrors. The calibration in rad/count is (reported in entry #1874) used for this measuremnt is:
| Pitch | Yaw |
| 0.038 [urad/count] | 0.027 [urad/count] |
We recall that that Input and end mirrors oplev use commercial PSD (thorlabs PDP90A) and the signal is amplified by a factor 100 with a SR560 and filtered with a 2nd order lowpass with cut-off frequency 100 Hz.
PIC 1: Piitch signal compared with ADC noise and dark noise (the noise measured when the laser is switched. Factor 100 amplification from SR560 still present)
PIC 2: Yaw signal compared with ADC noise and dark noise (the noise measured when the laser is switched off. Factor 100 amplification from SR560 still present)
PIC 3: Piitch signal compared with ADC noise and signal withoud the factor 100 amplification (red curve should be multipplied by a factor 100 to have the good calibration)
PIC 4: Yaw signal compared with ADC noise and signal withoud the factor 100 amplification (red curve should be multipplied by a factor 100 to have the good calibration)
