A super-resolution method for extraction of modal responses in wideband data

The paper presents a spectral estimation method to process coherently the wideband frequency domain field data of any object, and extract specific modal responses associated with wave propagation along the object. The problem is formulated in terms of well-known range processing used in radar waveform analysis. Thus, the data is modeled in terms of complex sinusoids, whose phase yields the decay/growth constants and the range associated with discrete scattering centers. Unlike previous approaches, the resulting amplitude and decay/growth constants are made frequency-dependent to capture the dynamic wideband behavior of the scattering mechanism. The method is illustrated by application to mode extraction for a cylindrically stratified scatterer.