Characterization and exploitation of lucky scintillations in HLA and VLA data from the 2006 Shallow Water Experiment

Abstract

The detection and localization of signals using large arrays is challenging in low coherence underwater environments. Poor spatial coherence is a consequence of signal wave front distortions caused by time-dependent three-dimensional spatial fluctuations in the sound speed from internal waves, fronts, and random medium effects such as turbulence. In an earlier paper (Lucky ranging with towed arrays in underwater environments subject to non-stationary spatial coherence loss in Proc. of ICASSP 2016, March 2016) we had proposed a new paradigm for array processing in poor coherence environments, motivated by real data observations, which exploited lucky moments or favorable scintillations when the signal wave front momentarily had little or no distortion. Here we examine the HLA and VLA data from the 2006 Shallow Water Experiment provided by the Woods Hole Oceanographic Institute to better understand and characterize the occurrence of lucky moments or favorable scintillations in actual data and how they can be utilized in array processing. Because of uncertainties in the HLA element positions, we developed a new empirical canonical correlation-based technique for the analysis utilizing lucky moments to blindly estimate the array manifold.