Reconstructing the sky location of gravitational-wave detected compact binary systems: Methodology for testing and comparison
The problem of reconstructing the sky position of compact binary coalescences detected via gravitational waves is a central one for future observations with the ground-based network of gravitational-wave laser interferometers, such as Advanced LIGO and Advanced Virgo. Different techniques for sky localization have been independently developed. They can be divided in two broad categories: fully coherent Bayesian techniques, which are high latency and aimed at in-depth studies of all the parameters of a source, including sky position, and "triangulation-based" techniques, which exploit the data products from the search stage of the analysis to provide an almost real-time approximation of the posterior probability density function of the sky location of a detection candidate. These techniques have previously been applied to data collected during the last science runs of gravitational-wave detectors operating in the so-called initial configuration. Here, we develop and analyze methods for assessing the self consistency of parameter estimation methods and carrying out fair comparisons between different algorithms, addressing issues of efficiency and optimality. These methods are general, and can be applied to parameter estimation problems other than sky localization. We apply these methods to two existing sky localization techniques representing the two above-mentioned categories, using a set of simulated inspiral-only signals from compact binary systems with a total mass of ≤20M_⊙ and nonspinning components. We compare the relative advantages and costs of the two techniques and show that sky location uncertainties are on average a factor ≈20 smaller for fully coherent techniques than for the specific variant of the triangulation-based technique used during the last science runs, at the expense of a factor ≈1000 longer processing time.
© 2014 American Physical Society. Received 19 December 2013; published 18 April 2014. J. V. was supported by the research program of the Foundation for Fundamental Research on Matter (FOM), which is partially supported by the Netherlands Organization for Scientific Research (NWO). N. C. was supported by the NSF Grant No. PHY-1204371. P. G. was supported by a NASA postdoctoral fellowship from the Oak Ridge Associated Universities. B. F., W. F. and V. K. were supported by the NSF Grant No. PHY-1307020, and B. F. was also supported by the NSF Grant No. DGE-0824162. V. R. was supported by a prize postdoctoral fellowship from the California Institute of Technology division of Physics, Mathematics & Astronomy and LIGO Laboratory. R. O. S. was supported by the NSF Grant No. PHY-0970074 and the UWM Research Growth Initiative. S. V. acknowledges the support of the National Science Foundation and the LIGO Laboratory. LIGO was constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the National Science Foundation and operates under cooperative agreement no. PHY-0757058.
Submitted - 1312.6013v1.pdf
Published - PhysRevD.89.084060.pdf