Underwater transient signal processing: marine mammal identification, localization, and source signal deconvolution

Processing marine-mammal signals for species classi cation and monitoring of endangered marine mammals are problems that have recently attracted attention in the scienti c literature. For classi cation it has been proposed to use methods appropriate for non-stationary signals, such as time-frequency and time-scale analysis. This paper shows that a factor that can signi cantly a ect results from marine-mammal signal processing is the impulse response of the ocean in which the signals propagate. The ocean is a dispersive propagation medium and, therefore, a ects the time-frequency characteristics of a propagating acoustic signal. Because of this distortion, feature selection should be performed after the oceanic impulse response has been deconvolved from the recorded signals. The paper also discusses localization of vocalizing marine mammals using matchedeld processing and shows how this becomes a part of the deconvolution process.