The goal of this project is to implement and demonstrate integrated unmanned aerial system (UAS) deployment of magnetometer technology to address wide area surveying in very shallow water environments. Rapid and cost-effective assessment of these shallow underwater sites is needed to understand the nature and extent of munitions contamination in important nearshore areas. Currently only manned aircraft-based or vessel-towed arrays are able to efficiently survey large areas (kilometer-scale), but they are not well-suited for particularly shallow or bathymetrically varying sites (where environments may be partially submerged or obstructed with natural or man-made obstructions) or for hydrodynamically energetic environments (surf or tidal areas). A particularly fast, simple, and cost-effective method for areal coverage mapping and infrastructure characterization has been established in the construction, property management and mining/quarrying business through the use of drone-based sensors. This project will focus on demonstrating an existing drone-based magnetometer system in realistic nearshore environments. The combination of new miniature atomic total field magnetometers, drone-integrated tow bird systems, mission planning and electro-optical imaging, and streamlined data processing methods presents a direct path to new unexploded ordnance (UXO) wide area surveying technology for delineating risk amongst sites.
Recent developments in UASs (or drones) provide new opportunities for geophysical surveying of munitions response sites by capturing high-resolution data and imagery not possible with conventional approaches. Drones are beginning to bridge the disparity in scale between traditional airborne remote sensing methods and ground-based monitoring techniques in various environmental applications. A wide range and selection of commercially available UAS platforms have entered the market that can be acquired off-the-shelf at increasingly lower cost. This availability and affordability has been complemented by rapid advances in the miniaturization of cameras, sensors, instrumentation, and data stores and transmission systems. Flying at lower altitudes (<10 m), the drone-based magnetometer remote sensing methodology allows for data capture at varying resolution and reduced costs. The methodology demonstrated in this project includes a combination of technologies: i) lightweight and highly sensitive atomic magnetometers; ii) commercially-available and highly maneuverable/controllable UASs (multi-rotor drones); and iii) integrated operational concepts and survey design strategies. Additionally, the investigators will demonstrate data processing workflows for UAS system noise compensation, data collection, mapping, and post-processing algorithms to generate work products to define munitions concentrations and nature and extent of munitions contamination.
For any airborne survey, the largest single factor affecting the survey cost is the cost of operating the survey aircraft and sensors at the site. These equipment costs are related to capital value, maintenance overhead, and direct operating costs. In addition, mobilization and demobilization costs can be substantial. UAS-based magnetometer systems tailored for wide area UXO surveying present an opportunity to improve data quality and safety at significantly reduced costs. Successful system demonstrations will result in a new integrated UAS-based technology and methodology for cost-effective utilization in shallow water production surveying.