Sparse sky grid for the coherent detection of gravitational wave bursts

TL;DR

This paper introduces a method to optimize sky grids for coherent gravitational wave burst detection, reducing computational costs by adapting the grid to the detector network's variable angular resolution.

Contribution

It proposes a novel procedure to design sky grids that ensure complete coverage with fewer vertices, tailored to the detector network's geometry.

Findings

Reduces computational cost of sky grid searches.

Provides adaptive sky sampling based on detector geometry.

Achieves complete sky coverage with fewer grid points.

Abstract

The gravitational wave detectors currently in operation perform the analysis of their scientific data jointly. Concerning the search for bursting sources, coherent data analysis methods have been shown to be more efficient. In the coherent approach, the data collected by the detectors are time-shifted and linearly combined so that the signatures received by each detector add up constructively (thus improving the resulting signal-to-noise ratio). This operation has to be performed over a sky grid (which determines the sky locations to be searched). A limitation of those pipelines is their large computing cost. One of the available degrees of freedom to reduce the cost is the choice of the sky grid. Ideally, the sky sampling scheme should adapt the angular resolution associated with the considered gravitational wave detector network. As the geometry of detector network is not regular (the detectors are not equally spaced and oriented), the angular resolution varies largely depending on the sky location. We propose here a procedure which designs sky grids that permit a complete sky coverage with a minimum number of vertices and thus adapt the local resolution.