Georgia, Jenne, Varun

We went to NLN_CAL_MEAS state and walked the 9 MHz and the 45 MHz modulation depth using the scripts 'step_45MHz.py' and 'step_9MHz.py' in /opt/rtcds/userapps/release/isc/h1/scripts

One issue with the measurement was that with the dither lines off the alignment was drifting at low frequencies: 10Hz to 20Hz. The key summary of the results is that the nominal O3 values are good and changing the modulation depth has little affect on the noise in DARM. I have attached 2 plots showing the low frequency changes in DARM. First for stepping the modulation depth of the 9MHz. Second one is for changing the 45 MHz modulation depth. The measurement template is saved at /ligo/home/varun.srivastava/LHO_work/O4_comm/2021_05_12_RF_reduction.