Motion parameter estimation of a fast moving sound source using the retardation effect

The radiated noise of moving sound sources (low flying aircraft, ships, etc.) can be used to detect and localize these objects. Besides this, the velocity vector can be estimated under certain conditions. The considerations presented in this paper deal with the estimation of these target parameters for low flying aircraft, at speeds comparable to signal propagation speed. At such velocities the retardation effect becomes very important. This effect will be described, and the reconstruction of the above metioned target parameters on the basis of bearing angle measurements will be shown.