High‐Frequency Rapid Geo‐acoustic Characterization

The Rapid Geo‐acoustic Characterization (RGC) algorithm was developed to perform geo‐acoustic characterization using the interference patterns of surface ships of opportunity in shallow water. It has been applied successfully at low frequencies to synthetic inversion workshop data and at sea in near real‐time. The RGC algorithm determines an effective sediment, which matches the slope (waveguide invariant) and spacing (reciprocal of the time ‐spread) of interference patterns as well as the fall off in range of the received level. In this paper, we evaluate the extension of the algorithm to mid and high‐frequency acoustic signals in shallow water. The issues explored are the robustness of the waveguide invariant, time ‐spread and TL slope at frequencies above 2 kHz. The algorithm will be applied to a synthetic data example with a known bottom in a range‐independent environment.