Coherent detection method of gravitational wave bursts for spherical antennas

TL;DR

This paper introduces a coherent detection method for gravitational wave bursts using spherical antennas, validated through detailed simulations that include realistic noise and detector imperfections, demonstrating improved detection efficiency and noise discrimination.

Contribution

The paper presents a new coherent analysis algorithm for spherical gravitational wave detectors, including a comprehensive numerical model and validation with simulated data, enhancing detection and localization capabilities.

Findings

Detection efficiency versus false alarm rate characterized.

Combined direction reconstruction reduces false alarms by a factor of 10.

Method effectively distinguishes gravitational wave signals from non-Gaussian noise.

Abstract

We provide a comprehensive theoretical framework and a quantitative test of the method we recently proposed for processing data from a spherical detector with five or six transducers. Our algorithm is a trigger event generator performing a coherent analysis of the sphere channels. In order to test our pipeline we first built a detailed numerical model of the detector, including deviations from the ideal case such as quadrupole modes splitting, and non-identical transducer readout chains. This model, coupled with a Gaussian noise generator, has then been used to produce six time series, corresponding to the outputs of the six transducers attached to the sphere. We finally injected gravitational wave burst signals into the data stream, as well as bursts of non-gravitational origin in order to mimic the presence of non-Gaussian noise, and then processed the mock data. We report quantitative results for the detection efficiency versus false alarm rate and for the affordability of the reconstruction of the direction of arrival. In particular, the combination of the two direction reconstruction methods can reduce by a factor of 10 the number false alarms due to the non-Gaussian noise.