OCEAN ACOUSTIC FIELD MATCHING - NORMAL-MODE FILTERING AND NON-GAUSSIAN SOURCES

Location of a submerged object is an important problem in ocean acoust ics. Classical interest in statistical sonar signal processing and con temporary interest in acoustic field matching are clear indications of the importance attached to this location problem. This paper produces two qualitative results concerning this quantitative subject. First, this paper integrates normal-mode field predictions with statistical s ignature analysis by constructing a boundary-value problem in the acou stic waveguide. This construction produces this new result the normal- mode filter is the unique acoustic pre-processor which does not confou nd deterministic waveguide correlation structure with stochastic sourc e covariance structure. Second, this paper investigates the origin of deterministic, Gaussian, and non-Gaussian source signatures by associa ting physical parameters with the classical Lindeberg central limit co nditions. This construction produces this new result: There are import ant objects that are not adequately represented either by infinitesima l points or by infinite surfaces. If receiver resolution is inadequate to resolve source complexity, these objects will exhibit a non-Gaussi an acoustic signature via an entirely linear progression from internal excitation, to source radiation, through waveguide propagation, and f inally to reception.