Figure 1 shows the data in DC read-out from Friday. The CMRF (coupling of SSFS/FMOD lines to DARM), varies around zero, with maybe an offset that is a factor few smaller than the fluctuations. Looking at the spectra of the coupling. There is a visible bump at 6mHz in the coupling. It would be interesting to understand what is fluctuating at that frequency, and try to improve it to make the CMRF more stable in time. Less clearly, but the DARM optical gain also seem to fluctuate at that frequency.
Francesco Di Renzo has worked on making the MONET bilinear analysis more accessible. It is sufficiently simple and well documented to start using it under one hour of learning time. Although the output is still a bit hard to navigate, and relies in many ways on reading a text file.
Analyzing the 1111Hz line, the dominant reason for coupling fluctuations are:
Figure 2 COMMp TX below 250mHz
Figure 3 DIFFp TX between 250mHz and 1Hz
Figure 4 shows all of the bilinear coupling that the analysis is able to explain based on the following channels tried for blinear coupling of 1111Hz x other channel:
Figure 5 just confirms the result of MONET using simple coherence between COMMp/DIFFp TX and the LSC_DARM_SSFS_LINE channels. In partiuclar the 6mHz is well visible on COMMp_TX, and coherent.