Coherent structure detection using wavelet analysis in long time-series

In this paper, we introduce two statistical techniques to detect coherent structures in long time-series: an intermittency rate estimator and an event-counting technique. The intermittency rate estimator calculates the fraction of time occupied by coherent structures, in contrast to incoherent noise. The event-counting approach estimates the number of discrete structures that occurred. In both cases, the wavelet transform and extensions of the coherent structure detector (CSD) are used to develop rigorous statistical approaches. The techniques are demonstrated on a 7 h wind time-series collected at the Wind Engineering Research Field Laboratory at Texas Tech.