Multistatic sonar with omnidirectional receivers

A multistatic sonar system, consisting of an all directions simultaneously illuminating projector and several omnidirectional receivers distributed across the surveillance area, is described. Different transmitter receiver configurations and a modified noise model which now includes reverberation are discussed. The radiation pattern of the projector need not be omnidirectional. Only the echo arrival times are transmitted to a central processor. This processor decides whether or not a target is present within the surveillance area and also approximately determines the position of a detected target. The coincidence test is nearly optimal (to about 1 dB equivalent monostatic direction index). With a multistatic system detected targets can be localized as accurately as with a monostatic system with a 25 dB direction index.