Robust test for detecting nonstationarity in data from gravitational wave detectors - art. no. 122002

It is difficult to choose detection thresholds fur tests of nonstationarity that assume a priori a noise model if the data are statistically uncharact erized to begin with. This is a potentially serious problem when an automat ed analysis is required, as would be the case for the huge data sets that l arge interferometric gravitational wave detectors will produce. A solution is proposed in the form of a robust time-frequency test for detecting nonst ationarity whose threshold for a specified false alarm rate is almost indep endent of the statistical nature of the ambient stationary noise. The effic iency of this test in detecting bursts is compared with that of an ideal te st that requires prior information about both the statistical distribution of the noise and also the frequency band of the burst. When supplemented wi th an approximate knowledge of the burst duration, this test can detect, at the same false alarm rate and detection probability, bursts that are about 3 times larger in amplitude than those that the ideal test can detect. Apa rt from being robust, this test has properties which make it suitable as an online monitor of stationarity.