Comparative analysis of underground and ground-level tilt and acceleration

The R-2 rotary seismograph can record rotating three components, MEMS acceleration, and tilt angle. In this study, the difference between ground acceleration and tilted background noise were analyzed using two phases of continuous observation data implemented in the ground and deep underground of the Huainan Deep Earth Laboratory. It was found that the deep earth environmental background interference was weaker, with background noise differences on the spectrum of up to 10 dB, showing that the Deep Earth Laboratory has superior conditions regarding low vibration and noise. The contrast before and after the skew correction of the MEMS acceleration using the tilt data revealed that the tilt had a non-negligible influence. The time-frequency analysis showed that the deep earth environment was favorable relative to the surface environment. The precision requirements of solid tide signal observations and shortcomings of existing instruments were also analyzed, proving the necessity of high precision observations in the deep earth environment.