Gravitational waves from coalescing binaries: a hierarchical signal detection strategy
The detection of gravitational waves from coalescing compact binaries would be a computationally intensive process if a single bank of template waveforms (i.e., a one step search) is used. We present, in this paper, an alternative method which is a hierarchical search strategy involving two template banks. We show that the computational power required by such a two step search, for an on-line detection of the one parameter family of Newtonian signals, is 1/8 of that required when an on-line one step search is used. This reduction is achieved when signals having a strength of ~8.8 times the noise r.m.s. value are required to be detected with a probability of ~0.95 while allowing for not more than one false event per year on the average. We present approximate formulae for the detection probability of a signal and the false alarm probability. Our numerical results are specific to the noise power spectral density expected for the initial LIGO.