Standoff Detection of Submerged Objects by the Optical Monitoring of Acoustically Excited 2D Surface Projections

Collisions between large vessels and marine mammals may result in animals being injured or killed and vessels can sustain damage. Serious injuries to passengers have occurred involving hydrofoil ferries, whalewatching vessels, and recreational craft. The current method of detecting marine mammals is arming watchstanders with binoculars in an attempt to locate and identify objects that may surface for fleeting time periods. IAW the Marine Mammal Protection Act, and as good stewards of the natural environment, it is incumbent on all U.S. mariners, including operators of DoD vessels, to avoid strikes and near misses of whales and other mammalian species. SARA proposes an Acoustic Scattering Surface Projection (ASSP) system where a continuous, sweeping, high-directive, and high-frequency acoustic signal is projected from a piezoelectric phased array onto a target. The acoustic scattering off the submerged target is projected onto the surface of the ocean where the surface perturbation is detected and its frequency parameter extracted at standoff distances by use of a low elevation angle infrared LiDAR system. In the current work, SARA proposes a research program to design innovative hardware and algorithms to detect and characterize near surface objects at standoff distances of up to 1 kilometer.