Processing of vector fields in underwater waveguides

Abstract

The ability to measure the scalar and vector properties of underwater acoustic fields has improved over the past decade with advancements in transducer technology. Investigations regarding the processing of such sensors have principally focused upon the exploitation of a vector sensor as a directional hydrophone and the ability to achieve significant spatial gains in an unusually small form factor (i.e., superdirectivity). These superdirective elements may then be examined in the framework of standard linear array processing techniques. Alternatively the scalar and vector sensors can be combined multiplicatively to generate estimates of the acoustic intensity vector. Several investigations regarding the detection of signals in noise with these multicomponent sensors have found that optimal linear processing produces a superior signal-to-noise ratio at the back end of the processor when compared to the intensity processor. While the intensity-based processing may not provide an optimal detector, it does provide insight into the fundamental nature of the underwater acoustic field by characterizing the energy flux density. This talk will discuss the effects of signal-model mismatch on the linear and multiplicative process by examining cases in which the assumed phase difference between pressure and particle velocity is not zero.