WIDE-BAND SOURCE LOCATION THROUGH FREQUENCY-DEPENDENT MODELING

This paper describes a method for locating multiple wideband sources u sing the signals received by an array of sensors. In the present appro ach, the problem of source location is treated as a frequency dependen t estimation problem. Each wideband source is received by the array as a vector signal. The spatial spectrum of this signal has a linear fre quency modulation (with respect to the usual frequency) which is chara cteristic of the source location. The frequency modulation may be reco vered by frequency dependent modeling over the entire frequency band. The models are estimated by a technique of ''model expansion,'' which consists in the replacement of the data by their projections on a basi s of functions of frequency. An invariant expanded model is fitted to these projections. It expresses the evolution of a spatial model with respect to frequency. An estimator based upon an eigen-decomposition o f a covariance matrix built from the observations, is discussed. This estimator leads to wideband versions of the high resolution estimators (minimum norm solution and MUSIC). Simulations will conclude the pape r and compare this estimator with the coherent signal subspace method.