There are more than 400 underwater sites in the United States that are suspected to contain military munitions that may pose a threat to human safety and the environment. Most sites are located in shallow water between 0 and 35 meters (m) depth. Technologies and approaches to detect munitions and explosives of concern (MEC) and assess the effects of their constituents on the environment and those who interact with it have been developed; however, the diversity of MEC types, their locations, environmental parameters, technologies, and approaches makes it difficult to conduct systematic comparisons of different methodologies. Hawaiʻi was suggested as a location to conduct technology comparisons because of its mild temperatures, range of underwater visibility, and variety of environmental settings. A munitions test range complex consisting of multiple demonstration sites for evaluating and comparing the efficacy of MEC detection tools was developed (ESTCP FY2022 - MR20-5292: Hawaiʻi Munitions Test Range Complex (HI_MTRC), Jan 2023) to allow customizability depending upon the requirements of ESTCP and potential technology developers. The HI_MTRC provides secure locations and resources to install rapidly deployable test sites for technology demonstrations. This project is a two-year demonstration by the Applied Research Laboratory (ARL) at University of Hawaiʻi (UH) to evaluate three technologies at HI_MTRC: the LiteWave Edge™, the Optical Munitions Detector (OMD), and the atomic magnetometer sensor. The OMD was previously the subject of a tabletop exercise completed by ARL at UH and the other candidate technologies have already undergone small-scale field testing. This program’s objective is to deploy and assess the technologies while confirming that Oʻahu’s test sites are suitable for operational demonstrations. Other sensing technologies matching optical and physical properties to characterize underwater sites may use HI_MTRC during the two-year program.

The ARL at UH owns and operates a fleet of uncrewed vehicles (UxVs) and support equipment including more than a dozen uncrewed aerial vehicles, the commercial off- the-shelf Wave Adapted Modular Vessel, and a light autonomous underwater vehicle. These assets have been integrated to support multiple missions including inspection of littoral zones in response to natural and man-made events, underwater change detection and environmental monitoring. The HI_MTRC effort also highlighted the benefits of frequent, repetitive field work to assess technology performance under variable conditions. ARL at UH implemented the approach developed by the Pacific Northwest National Laboratory of installing real-time kinematic Global Navigation Satellite System sensors on floats tethered adjacent to seeds (blind seeding is a quality control process on MR projects where project personnel intentionally place munition like objects [seeds] in the MR project demonstration area to test and validate the UXO detection, localization, and classification technologies) resting on the seabed to geolocate objects. This program will assess the performance of inertial measurement units in Hawaiian environments and evaluate if movement of seeds occurs between their placement on the seafloor and their retrieval. The three technologies anticipated to be used at HI_MTRC for this project have all been used in previous SERDP/ESTCP projects and have demonstrated potential to be effective at detecting MEC in shallow water environments.

Comparing the performance of various technologies will allow the objective evaluation of detection capabilities and confirmation of the suitability of HI_MTRC for assessments. In addition to improving operational capabilities at a rapidly deployable demonstration site, this program will provide data to allow each technology to evaluate their operational use to detect MEC. (Anticipated Project Completion - 2026)