Demonstration of Crawler-Towed Sensor Technologies in Challenging Nearshore Sites
Dr. Gregory Schultz | White River Technologies, Inc.
In this project, the team from White River Technologies, Inc., Fugro GeoServices, Inc., and the U.S. Army Corps of Engineers Coastal and Hydraulics Laboratory (CHL) will implement and demonstrate technologies for characterization of unexploded ordnance (UXO) in challenging nearshore environments. The boundary between land and sea has historically been of strategic military importance, thus numerous training ranges have been established in this environment. This environment poses unique technical challenges to the detection and classification of UXO including highly variable spatio-temporal conditions, e.g., tidal currents and dynamic wave energy, variable burial depth and mobility of UXO, and presence of dense coastal vegetation.
The project’s objective is to fill the capability gaps existing in UXO characterization in these environments through use of innovative amphibious platforms and integrated sensor technologies, deployment procedures, and data analysis specific to the nearshore environment. To achieve this objective, the team will evaluate existing amphibious vehicles in terms of their technical specifications and applicability to different nearshore environments. The impact of each platform on the environmental will also be assessed due to the potential operation of the vehicle in environmentally sensitive areas. They will demonstrate the ability to collect high quality electromagnetic (EM) data from an amphibious platform in realistic nearshore environments while using integrated navigation and control for the acquisition of correlated high quality position information. The integrated system will be validated and tested in one engineering test and two live site demonstrations.
This project will integrate a commercially available Geonics EM 61S sensor, commercial off-the-shelf positioning sensor hardware and software onto a tow platform specifically designed for nearshore environments. The tow platform will be towed using an amphibious vehicle. Positioning sensor hardware for consideration includes real-time kinematic differential global positioning system (RTK-DGPS), altimeter, integrating navigation system (INS), and ultra-short and long baseline (USBL/LBL) acoustic systems. The tow platform will be designed for collection of low-noise EM data in harsh conditions such as breaking waves (surf zone) and dense vegetation (salt marshes). An engineering test will be performed at CHL’s Field Research Facility to assess tow platform design, characterize EM noise due to deployment in nearshore environments, and develop mission plans and operating procedures for operational use of the technology. During this test, an advanced EM sensor with multi-axis receivers will be evaluated for performance improvements compared to the EM61, including noise characteristics and acquisition of data for creation of classification features. The test’s success will be based on EM sensor performance metrics (signal-to-noise ratio, probability of detection), positional accuracy, and effectiveness of the towed platform. Subsequent demonstrations will validate and test the performance of the sensor platform towed by a remotely-operated crawler. These demonstrations will be conducted at representative marine sites, presenting a realistic UXO remediation environment for demonstration of the system. Live site demonstration metrics include probability of detection, coverage rate, and ease-of-use of the demonstrated system.
No system currently exists for characterizing UXO in nearshore marine environments, which require continuous EM sensor coverage onshore to offshore. Effective classification of UXO in these environments is a key requirement for cost-effective cleanup of contaminated marine sites. Successful demonstration of the technology will result in an integrated amphibious sensor technology for UXO remediation and characterization applications in challenging nearshore environments. (Anticipated Project Completion - 2016)