Application of space-time spectral analysis for detection of seismic waves in gravitational-wave interferometer

TL;DR

This study applied space-time spectral analysis to seismic data from the Virgo interferometer to detect and characterize seismic waves, aiming to improve gravitational-wave detector sensitivity by understanding local seismic noise.

Contribution

The paper introduces a space-time spectral analysis method for detailed seismic wave detection and characterization in gravitational-wave detector environments.

Findings

Detected seismic waves at 5.5 Hz and 17.1 Hz frequencies.

Identified industrial complex and nearby object as sources.

Results will aid in better noise estimation for Virgo.

Abstract

Mixed space-time spectral analysis was applied for the detection of seismic waves passing through the west-end building of the Virgo interferometer. The method enables detection of every single passing wave, including its frequency, length, direction, and amplitude. A thorough analysis aimed to improving sensitivity of the Virgo detector was made for the data gathered by 38 seismic sensors, in the two-week measurement period, from 24 January to 6 February 2018, and for frequency range 5--20 Hz. Two dominant seismic-wave frequencies were found: 5.5 Hz and 17.1 Hz. The possible sources of these waves were identified, that is, the nearby industrial complex for the frequency 5.5 Hz and a small object 100 m away from the west-end buiding for 17.1 Hz. The obtained results are going to be used to provide better estimation of the newtonian noise near the Virgo interferometer.