This is to help troubleshoot the excess noise measured earlier.
The following channels were measured at GPS times 1258586880 s and 1258597457 s, corresponding to low and high Power Recycling Gain (PRG) respectively.
Excess noise was seen between 25-110 Hz in the high PRG case when compared to the low PRG case in the following channels:
C1:LSC-CARM-IN1_DQ (shown in Attachment 1 where the reference is low PRG)
C1:ALS-Y_ERR_MON_OUT_DQ
C1:ALS-BEAT{X,Y}_FINE_PHASE_OUT_DQ
C1:SUS-ETM{X,Y} _SENSOR_{LL,LR,UL,UR}
C1:ALS-TRX_OUT_DQ
Surprisingly, it was also seen to a smaller extent in (refer Attachment 3)
C1:SUS-ITMX_SENSOR_{LL,LR,UL,UR}
A different type of noise spectrum, attributed to known electronic effects, was observed for
C1:SUS-ITMY_SENSOR_{LL,UL} (refer Attachment 2)
These did not show any significant change in the noise spectrum:
C1:LSC-DARM-IN1_DQ (shown in Attachment 1 where the reference is low PRG)
C1:ALS-X_ERR_MON_OUT_DQ
C1:ALS-TRY_OUT_DQ
C1:SUS-ITMY_SENSOR_{LL,LR,UL,UR}
C1:SUS-ITMY_SENSOR_{LR,UR} (refer Attachment 2)
Broadband noise in:
C1:LSC-PO{X,Y}11_I_ERR_DQ
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