Horizontal samples of a point source in a shallow water waveguide are processed by the Prony method. First, when the source position is known, a high resolution estimation of the normal mode parameter Km (the horizontal component of mode wavenumber) can be obtained. Owing to the weak damping process, βm, the modal attenuation coefficient, can be obtained by using a modified Prony method. In this article, an ‘‘interval average and iterative’’ approach is proposed. Numerical examples illustrate that a 10−4 resolution of Km (150-Hz frequency) is provided by a 500-m data length, roughly an order of magnitude smaller than the data length required by the linear spectrum analysis technique. Second, when the source position is unknown but the waveguide characters (Km, βm) are known, the same procedure can be used for source position estimation. Some numerical examples in typical shallow water are presented.

Horizontal samplings of a point source in a shallow water waveguide are processed by Prony's method. First, when the source position is known, a high resolution estimation of the normal mode parameter km—the horizontal component of mode wavenumber, can be obtained. Owing to the weak damping process, βm, the modal attenuation coefficient can be obtained by using a modified Prony's method. In this paper, an “interval average and iterative” approach is proposed. A numerical example illustrates that, a 10−4 resolution of km (150-Hz frequency) is provided by a 500-m data length, roughly an order of magnitude smaller than the data length required by the Hankel transformation technique. Second, when the source position is unknown but the waveguide characters (km, βm) are known, the same procedure can be used for source position estimation. Some numerical examples in typical shallow water waveguide will be presented.