Active source detection in a dispersive multiple-reflection environment

A signal propagating in a shallow water waveguide is subjected to (a) multiple reflections off the ocean boundaries and (b) distortion because of the dispersive properties of the propagation medium. Because of these corruptions, the received signal differs substantially from the transmitted signal. Although the transmission is sometimes exactly known, the received signal cannot be described in detail because of inadequate knowledge of the ocean impulse response. Ignoring the effects of the ocean on the signal, or representing them inaccurately, can lead to deterioration of the detection statistics. This paper compares the performance of methods designed for distortion-free, multiple-reflection transmission in realistic, dispersive environments. Two existing methods, the RCI (replica correlation integration) processor and the simple source-receiver matched-filter, and a new detector are evaluated. The impact of distortion on signal transmission is assessed by comparing the distortion-free methods to the optimal processor, which models the effects of the propagation medium on the signal.