Yesterday, it was mentionned in LHO aLOG 4858 that transfer functions measured on BSC1 were different from what we expected. This morning, I ran some simulations to evaluate if the extra modes seen in the [5-8]Hz frequency band would create some difficulties in the control design.

For the test, I used the BSC6 damping and isolation filters.

The 12 main transfer functions once the ISI is damped:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H1/ITMY/Data/Figures/Transfer_Functions/Simulations/Damped/

• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_RX_to_ST1_L4C_RX_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_RY_to_ST1_L4C_RY_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_RZ_to_ST1_L4C_RZ_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_X_to_ST1_L4C_X_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_Y_to_ST1_L4C_Y_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_Z_to_ST1_L4C_Z_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_RX_to_ST2_GS13_RX_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_RY_to_ST2_GS13_RY_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_RZ_to_ST2_GS13_RZ_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_X_to_ST2_GS13_X_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_Y_to_ST2_GS13_Y_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_Z_to_ST2_GS13_Z_2012_12_04.fig

The 12 main SISO TF used for the control design (between every steps, the MIMO response is used) are given below:

https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H1/ITMY/Data/Figures/Transfer_Functions/Simulations/Isolated/

• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_RX_to_ST1_SS_RX_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_RY_to_ST1_SS_RY_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_RZ_to_ST1_SS_RZ_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_X_to_ST1_SS_X_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_Y_to_ST1_SS_Y_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_Z_to_ST1_SS_Z_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_RX_to_ST2_SS_RX_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_RY_to_ST2_SS_RY_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_RZ_to_ST2_SS_RZ_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_X_to_ST2_SS_X_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_Y_to_ST2_SS_Y_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_Z_to_ST2_SS_Z_2012_12_04.fig