Potential for extraction of scatterer and waveguide characteristics from reverberation spectrograms

Coherent structure in the spectrograms of broadband reverberation in the mid frequency regime has been measured at various sites by various researchers. Recently, very broadband data collected over three and a half octaves on the Malta Plateau during the Clutter 09 experiment conducted by the NATO Undersea Research Centre show very clearly the striation structure of interest. In this paper, the theory of why the striations appear in the spectrograms of the reverberation is briefly reviewed, and the extraction of channel and scatterer information from the time-frequency content of the signal is explored using holomorphic processing. To constrain these studies, we exploit the availability of broadband reverberation models which contain all the features of the data, are noise free and have zero uncertainty, and have known waveguide and scatterer characteristics to compare with the extracted information. The Clutter 09 data are also evaluated using the method, and the resolution and robustness of the approach are discussed.