Autonomous seafloor geotechnical property sensor

Omni Technologies, Inc. (OTI) is proposing to develop an autonomous, geotechnical survey tool for mapping marine sediment properties. Our approach is to leverage one of the available man-portable autonomous underwater vehicles (AUVs) and develop an instrument capable of surveying a wide area. OTI proposes to combine a geotechnical instrument(s) with an acoustic sub-bottom profiler to combine large area coverage with accurate results. OTI will develop the sub-bottom profiler for a man-portable AUV based on our experience building medium size AUV profiler systems. While sub-bottom profilers coupled with sidescan sonar provide wide coverage of the seafloor, sediment classification from these acoustic data requires ground truth using geotechnical measurements. OTI will investigate various geotechnical sensors that can be autonomously deployed from a small AUV to obtain sediment shear strength at locations determined autonomously by the AUV during the survey. Reliable estimations of shear strength have been obtained with penetrometers, making them the leading candidate for our sensor package. Additional parameters (grain size, porosity, etc.) would be also be helpful and OTI will investigate alternative or additional sensors during Phase I.