A new waveform consistency test for gravitational wave inspiral searches

Abstract

Searches for binary inspiral signals in data collected by interferometric gravitational wave detectors utilize matched filtering techniques. Although matched filtering is optimal in the case of stationary Gaussian noise, data from real detectors often contain ‘glitches’ and episodes of excess noise which cause filter outputs to ring strongly. We review the standard χ2 statistic which is used to test whether the filter output has appropriate contributions from several different frequency bands. We then propose a new type of waveform consistency test which is based on the time history of the filter output. We apply one such test to the data from the first LIGO science run and show that it cleanly distinguishes between true inspiral waveforms and large-amplitude false signals which managed to pass the standard χ2 test. Future searches may benefit significantly from applying this new type of waveform consistency test in addition to the standard χ2 test.