Time-frequency tracking using multi-window local phase analysis

The analysis of signals consisting of multiple components with non-linear frequency modulation is required in a large number of applications, including the study of marine mammals vocalizations. This analysis has multiple motivations, such as investigating the impact of anthropogenic noise on marine mammal behavior, and species identification to avoid collision between ships and marine mammals. Such applications are normally conducted in a Passive Acoustics Monitoring (PAM) context, where there is low SNR together with very little a priori knowledge on the signals being analyzed. Recently, time-frequency tracking based on local analysis of the instantaneous phase has been successfully applied to underwater signals. In this paper, we present a robust version of this method, based on the use of the multiple analysis windows. The results provided for simulated and real signals demonstrate improved tracking of the instantaneous frequency in noise.