Previous ESTCP project MR19-5073 demonstrated the effectiveness of the towed UltraTEMA-4 platform for marine Advanced Geophysical Classification (AGC) at the Sequim Bay demonstration site in Washington State. The results successfully demonstrated the system can detect and classify medium-sized ordnance, at minimal standoff distances in water depths between 5 and 85 feet, in a single-pass.

Building on the success at Sequim Bay, Tetra Tech, along with their partners Gap Explosive Ordnance Detection (GapEOD) and Black Tusk Geophysics (BTG), plan to deploy the UltraTEMA-4 platform at a live site demonstration. The project objective is to gather usable data at a site with a known history of munitions contamination to facilitate the Department of War (DoW) defining specifications and acceptance criteria (e.g., measurement quality objectives) for dynamic positioning, detection and classification of sources. Additionally, the project objective includes the development of initial training materials such as standard operating procedure instructions. These objectives will further facilitate the transfer of this technology to the broader munitions response industry.

The UltraTEMA-4 platform is an integration of the following three subsystems:

1. GapEOD’s multi-component multi-sensor UltraTEM system, which uses time-domain electromagnetic induction (EMI) to detect and characterize buried metal.
2. Tetra Tech’s towed-electromagnetic array system (TEMA), which combines commercially available surface and subsurface positioning and attitude components (including post-processed positioning) with customized fabrication, integration and system-specific EMI detection equipment.
3. BTG’s BTField software for data acquisition and UXOLab for data processing and classification of marine EMI data.

Similar to the benefits of AGC for terrestrial sites, an advanced marine sensor facilitates informed dig decisions and lowers investigative and remediation costs at underwater sites by reducing the need to dive on target locations. The UltraTEMA-4 system provides single pass classification, which eliminates the need for multiple surveys. However, the technology is in an earlier emergent stage compared to terrestrial systems. The results of this project further an understanding of specific limitations of the UltraTEMA-4. The project outputs enable DoW to further communicate system capabilities to technology end users and stakeholders with data-driven results. This process ultimately increases industry awareness of this advanced marine sensor technology development and furthers confidence in the ability to establish appropriate project goals and subsequently achieve those goals at DoW and civilian underwater munitions sites. (Anticipated Project Completion - 2027)