Today I implemented the sensor correction at the BS.
To make the inter-calibration between the seismometer, LVDT, and geophones, along L and T, I measured the transfer function between ground and IP using the procedure reported in log 20873.
Here are the values of the calibration factors:
I implemented in the MEDM these values and I implemented the same filters used in the TypeA suspension.
Pic.1 shows the TFs from ground to GEO-SEISM.
Pic.2 and Pic.3 show the spectra acquired by the LVDTs before and after the implementation of the sensor correction. Looking at these plots, it is possible to see that in the frequency range [0.1 1]Hz, the rms of the LVDT signals is reduced by a factor of 4.6 and 4 at 200 mHz along L and T respectively. It seems to be working fine.
I left the sensor correction on so to check its performance when the IFO is locked.