Path resolution by coherent averaging: trading spatial and temporal degrees of freedom

The multipath passive location problem with wideband source signal is considered. Spatio temporally based high resolution algorithms are presented that assume no knowledge of the second order statistics of the emitted signal. With these methods, the restriction on the size of the receiving aperture commonly imposed by spatial-only high resolution algorithms is substituted by a global condition on the total number of spatial and temporal degrees of freedom. This approach shows that the frequency contents of the emitted signal are effectively used to compensate for the eventual deficiency in the number of available sensors, extending the number of detectable paths for an array of a given size