Patent ID: 6445647
Filing Date: 2002-09-03
Classification: G01S,G10K

Abstract:
A wideband-to-narrowband conversion method, comprising the steps of:(a) receiving an acoustic wideband signal and, in response thereto, generating a spatial Wigner bilinear kernel output signal, said acoustic wideband signal being initially incident upon an array of linear acoustic transducers and outputted as an analog acoustic wideband signal by the array of linear acoustic transducers that is digitized before said generating of said spatial Wigner bilinear kernel output signal therefrom, said generating of the Wigner bilinear kernel output signal producing spatial Wigner bilinear kernel outputs for paired transducers of said transducer array symmetrically positioned relative to and in opposite directions from a center of said transducer array by multiplying the digitized outputs of said paired transducers with one another; and (b) receiving and spatially bandpass filtering said spatial Wigner bilinear kernel outputs to remove a wideband low frequency portion as well as any unwanted noise therefrom and retain and output only a narrowband portion thereof.