The objective of this project is to further demonstrate the performance of a system that uses a MultiSensor Towbody (MuST) to deploy detection, classification, and geolocation hardware from a surface vessel. The system design was carried out under a SERDP effort MR-2501. MuST was developed and tested via the ESTCP project MR18-5004.

This project is a three-year effort that includes three field operations. The second and third field efforts will be in operational environments specified by ESTCP and Naval Facilities Engineering Systems Command/United States Army Corps of Engineers. These are anticipated to be carried out in March 2025 and March 2026. The first effort would be a formal demonstration (including demonstration of the overall sensor integration and software package development) in Sequim Bay in September 2023 with the following performance objectives: (1) percent of seeded unexploded ordnances (UXO) detected/correctly classified (Pc) > 0.94, and less than five false alarms within blind test area, (2) geolocation to within 2 meters for 90% of the targets of interest, and (3) completion of all survey lines at each approach angle each day.

The baseline MuST system comprises:

- Low-frequency, high-grazing angle, high-bandwidth acoustics system (EdgeTech Buried Object Scanning System — eBOSS)

- High-frequency, mid-to-low-grazing angle side scan sonar (EdgeTech 2205)

- High-frequency Multibeam sonar (RESON T50)

• FOCUS-3 towbody manufactured by MacArtney Underwater Technology
• Three sonar systems mounted on the FOCUS-3

• Shipboard handling system for the FOCUS-3
• Shipboard data acquisition as well as analysis hardware and software

Broadband sonars operating in the kHz to 10’s of kHz regime have shown promise in detecting/classifying buried (and proud) mine-like objects at performance levels and area coverage rates superior to other modalities. Previous SERDP and ESTCP research efforts indicate that the same may be true for munitions but demonstration of the performance in an operational context has not been carried out. This project seeks to address this deficiency by further demonstrating the capabilities of a surface ship/towbody solution that minimizes the in-water, at-risk hardware.