Abstracts

“UXO Characterization for Underwater Acoustic Test Beds” by Dr. Aubrey España (MR20-1443 and MR23-3978)

As reflected in SERDP Statement of Need MRSON-20-C1, the detection and identification of UXOs through sonar interrogation require that system algorithms be robust to a wide variety of environmental and target conditions. This presentation will focus on two complementary projects that aim to make headway in this problem. The first project, MR20-1443, utilizes validated hybrid modeling techniques coupled with knowledge of underlying physics behaviors to create a classification architecture that can assist post-mission analysis of data collected by the downward looking Multi-Sensor Towbody (MuST). A particular focus is studying the scattered response from simple UXO-like shapes and connecting it to well-established physics theory governing the coupling and scattering of sound from cylindrical elastic objects. Complementary to this is project MR23-3974 whose objective is to fully characterize a set of inert UXO currently in use at the PNNL Test Bed in Sequim Bay. High-fidelity CAD models are built for a set of inert UXO. These are imported into a finite element software. Variability is then introduced in the physical characteristics and the simulation tool TIER is used to generate synthetic data. This data can then be used to quantitatively measure the effects on a sonar system’s ability to correctly identify the target.

“Target-in-the-Environment Response Tool” by Dr. Steven Kargl (MR23-7943)

Through-the-sensor simulated sonar signals can be used to assess the design of a sonar platform or a possible modification to an existing platform. Simulated signals can also augment available measured data in the training and testing of classification algorithms. The TIER model is a fast acoustic model that can predict stave-level sonar signals under various environmental and geometrical conditions. The TIER model is an Applied Physics Laboratory, University of Washington in-house model that has undergone continuous development, testing, and validation with partial support under SERDP MR-1665, MR-2231, MR-2505, and MR19-1234. The current implementation is a high-quality research code, but it requires some familiarity with its internal implementation details and acoustic scattering in an underwater environment. The recently funded ESTCP MR23-7923 seeks to package the TIER model into a tool that can be used by other munition response researchers and contractors. During this presentation, features of the TIER model will be reviewed and an overview of current progress towards package tools will be given.

Speaker Biographies

Dr. Aubrey España is a Principal Physicist in the Acoustics Department of the Applied Physics Laboratory at the University of Washington in Seattle. Over the last 15 years, she has participated in multiple field experiments including TREX13, BAYEX14 and CLUTTEREX17, and has led the data acquisition strategy during those experiments. She has served as a principal and co-principal investigator on numerous projects funded by SERDP and the Office of Naval Research. Her work has evolved over the years to include classification strategies and performance estimation in the context of UXO remediation and underwater mine countermeasure operations and continues to focus on utilizing physics to understand and predict the observed scattering from underwater objects. Dr. España received bachelor’s and doctoral degrees in physics from Washington State University.

Dr. Steven Kargl is a senior principal research physicist with the Applied Physics Laboratory at the University of Washington in Seattle. His current areas of research include the scattering of sound from objects and wave propagation within marine environments. He has served as a Principal Investigator on several SERDP and ONR grants and contracts, which addressed detection and classification of underwater munitions near a water-sediment boundary. SERDP MR-2231 and MR-2505 received Project of the Year designations in 2013 and 2019, respectively. Steven is a Fellow of the Acoustical Society of America. He received bachelor's degrees in physics and mathematics from the University of Dayton, and master’s and doctoral degrees in Physics from Washington State University.