The sensor correction filter, reported in entry 23508, was designed using an upper limit of the microseismic motion (see 23507). In this entry, I report the calculated noise of the corrected LVDT when the ground motion has a midsize amplitude.
I used the ASD measured on the 4th of December 2022, when the secondary microseismic peak reached 2 um/rtHz approximately. The description of the figures is as follows:
- Low frequency noise empirical model (includes seismometer noise and ground motion too).
- Seismic noise, modified at low frequencies to be able to use it in the noise budget calculation.
- Noise budget calculation.
As can be seen in Fig. 3, the reduction of the rms noise of the LVDT is a factor of 19, integrated from 10 to 0.006 Hz, and the reduction of the contribution of the secondary microseismic peak is also substantial.
Based on this result, and the one reported in entry 23528, it seems safe to use the sensor correction filter for all microseismic conditions.
