Using the data measured yesterday (klog 22217), I calculated the calibration factor between the output of seismometer on the ground (2nd floor) SEIS and the term (GEO-LVDT).
Per klog 20873, the aim is to calculate a such that a * SEIS = GEO-LVDT, in a frequency range where there is high coherence (Fig. 1). The value of a was calculated by minimizing the RMS value of the function (GEO-LVDT) - a * SEIS.
The results are as follows:
- Frequency range: from 160 to 500 mHz.
- IP-L, Y Arm: a = 1.21104 (Fig. 2).
- IP-T, X Arm: a = 1.17220 (Fig. 3).
These calibration factors still need to be written in the appropriate filter banks, and then the performance of the sensor correction can be assessed.