Unexploded Ordnance Characterization and Detection in Muddy Estuarine Environments
Dr. Arthur Trembanis | University of Delaware
SERDP has recognized a need for better quantitative understanding of the impact of coastal environments on UXO behavior (MRSON-17-01). While current studies are addressing the mobility and detection of UXO in sandy coastal areas (e.g. Calantoni SERDP MR-2320, Traykovski MR-2319, Puleo MR-2503), a significant data gap has been identified regarding UXO in shallow, muddy environments. The majority of military testing ranges with potential UXO have been linked to characteristically muddy environments (SERDP Munitions Mobility and Modeling Workshop, Dec. 8-9, 2015). This study works to address this data gap.
Using a shallow estuarine site in the Delaware Bay, this study will 1) monitor the mobility and behavior of sensor-integrated surrogate munitions in muddy environments using a high-accuracy acoustic positioning system, 2) directly observe surrogate munition response to hydrodynamic forcing through instrumented bottom frame time-lapse hydrodynamic data and sonar imagery, and 3) monitor site changes and test an autonomous underwater vehicle-borne magnetometer through repetitive site surveying.
Surrogate UXO, modified with acoustic tracking devices and inertial motion units (IMU), will be deployed at a previously characterized muddy estuarine site. The surrogates will be monitored for changes in mobility and burial using the VEMCO positioning system, an off-the-shelf acoustic positioning system that is capable of tracking the position of multiple acoustic tags with accuracies down to 10 cm. Concurrently, time-series acoustic imagery and hydrodynamic sensors will be deployed to characterize UXO response to varied hydrodynamic conditions and compared to site-wide surrogate behavior. A series of repetitive surveys will be conducted using a magnetometer specifically designed for UXO detection on an autonomous underwater vehicle (AUV). Survey results will be compared to longterm acoustic positioning of the surrogate UXO to determine the effectiveness of the magnetometer for efficiently and effectively locating UXO in shallow, muddy environments.
This study will help inform parameters for UXO mobility and behavior in storms and muddy environments, and the anticipated data will be made available for integration into the existing expert system modeling of UXO burial and mobility (e.g. Underwater Munitions Expert System, Rennie MR-2227, SERDP Munitions Mobility and Modeling Workshop, Dec. 8-9, 2015). Additionally, the proposed study will provide important data regarding the ideal design for test beds to evaluate sensor capabilities in muddy environments, including the use of AUV magnetometry for UXO Wide-Area Assessments in muddy environments.