Modeling and Experiment of the Suspended Seismometer Concept for Attenuating the Contribution of Tilt Motion in Horizontal Measurements

TL;DR

This paper proposes a mechanical suspension approach to reduce tilt motion effects in horizontal inertial sensors, enhancing their performance without auxiliary sensors, supported by modeling, simulations, and experimental validation.

Contribution

It introduces a novel mechanical suspension technique to mechanically filter tilt in inertial sensors, avoiding the noise limitations of tilt measurement methods.

Findings

Effective tilt attenuation demonstrated through modeling and simulations

Experimental results confirm the viability of the suspension approach

Maintains translation sensitivity in the target frequency band

Abstract

Tilt-horizontal coupling in inertial sensors limits the performance of active isolation systems such as those used in gravitational wave detectors. Inertial rotation sensors can be used to subtract the tilt component from the signal produced by horizontal inertial sensors, but such techniques are often limited by the sensor noise of the tilt measurement. A different approach is to mechanically filter the tilt transmitted to the horizontal inertial sensor, as discussed in this article. This technique does not require an auxiliary rotation sensor, and can produce a lower noise measurement. The concept investigated uses a mechanical suspension to isolate the inertial sensor from input tilt. Modeling and simulations show that such a configuration can be used to adequately attenuate the tilt transmitted to the instrument, while maintaining translation sensitivity in the frequency band of interest. The analysis is supported by experimental results showing that this approach is a viable solution to overcome the tilt problem in the field of active inertial isolation.