Properties of circular sparse arrays for underwater, broadband, high frequency source localization

This paper describes some of the properties of receiving sparse circular arrays, derived by Matlab^® simulations and partially verified by water tank tests. The context is that of underwater angular localization of quasi-stationary, broadband, high frequency sound sources. And the system here described could also be regarded as a multi-sensors interferometer. Spurious responses, a drawback of sparse array configuration, are analyzed and means for their control indicated. Beamwidth is shown to depend on signal bandwidth, rather than on central frequency, as for the basic interferometer. Processing gain for a stationary source indicates interesting operational performance vs. various type of sources. Limits due to interference are analyzed, and a method for their reduction is presented, based on incoherent processing of output data.