In an important milestone, scientists have shown that low-frequency sonar can be an effective method for detecting and classifying underwater munitions in a real-world, open water setting. In work funded by SERDP, Dr. Steven Kargl of the University of Washington collaborated with a half dozen research teams in conducting a complex, coordinated experiment in the Gulf of Mexico.

In prior laboratory experiments and carefully controlled tests in ponds, low-frequency sonar has shown promise as a method to detect and classify underwater munitions. Determining if this acoustic technique would work in an open water environment with multiple variables is the next step in assessing its viability for routine use.

In the SERDP project, conducted in the summer of 2013, teams set up a series of jigs in the Gulf, placed various objects, including munitions, on the sandy bottom and among the rocks on the sea floor, then used sonar to detect and classify the items. Along the way, the research teams encountered a number of real-world interferences including fish using the jigs as artificial reefs that had to be overcome.

The high-quality data set collected through this project shows that low-frequency sonar can be effective in detecting and classifying underwater munitions in real-world conditions. The development of a sonar-based survey system would provide DoD with an efficient means of collecting accurate information about the location and identity of underwater munitions to support management or cleanup.

For successfully coordinating this complex multi-team project, Dr. Kargl received the 2013 SERDP Project-of-the-Year Award for Munitions Response. Project Summary 

• Dr. Kevin L. Williams, Applied Physics Laboratory, University of Washington
• Dr. Aubrey L. España, Applied Physics Laboratory, University of Washington