Pulse Propagation and Bistatic Scattering

Abstract

A set of pulse-propagation coupling equations is derived. They couple the output electrical signal at a point element in a receive array to the transmitted electrical signal at the input to a transmit array via the complex frequency response of a fluid medium (e.g., air or water). The pulse-propagation coupling equations are based on linear, time-variant, space-variant, filter theory, the principles of complex aperture theory and array theory, and solving a linear wave equation, which includes satisfying all boundary conditions, including the boundary condition at the source. They can be used to accurately model the propagation of small-amplitude acoustic pulses in the ocean for a bistatic scattering problem. Three different bistatic scattering problems are considered: (1) no motion, (2) only the discrete point scatterer is in motion, and (3) all three platforms (the transmitter, discrete point scatterer, and receiver) are in motion. Specific examples on the use of the pulse-propagation coupling equations are given for the three different bistatic scattering problems.