Studies in low to mid-frequency acoustic variability and support for the FORA replacement acquisition system

The research given in this proposal would have a direct impact in Ocean Acoustics topic areas including Shallow-water Acoustics, Deep-water Acoustics, and Arctic Acoustics. This work would perform research in the interest of measuring and analyzing acoustic variability in the low- to mid-frequency regime in several measurement scenarios and parameters. This includes: 1) a continuation of PennStates effort in characterization of reverberation coherence statistics, 2) investigation into the cause of instability in mid-frequency waveguide invariant and associated spatial coherence, and 3) laying the ground work for potential measurements of convergencezone and near-surface duct propagation stability in seasonally ice-covered arctic regions (measurements that, as known to the author, would be a first). Additionally, this proposal includes funding in support of the ONR Five Octave Research Array (FORA) replacement acquisition system the Three Octave Research Array (THORA) which is maintained and operated by the Applied Research Laboratoryat the Pennsylvania State University (ARL-PSU), but funded by and operated at the discretion of the ONR Ocean Acoustics program (ONR-OA).