BIOACOUSTIC SPECTROSCOPY OF THE BLACK SEA
Abstract
Bioacoustics Spectroscopy of the Black Sea ABSTRACT The performance of modern naval tactical active mid-frequency sonars is strongly affected by Volume Scattering Strength (VSS), Bio-attenuation (BA), and the target strength (TS) of fish schools in biologically intense regions, such as the Black Sea. High values of VSS and BA limit detection range, whereas bio-clutter, i.e., echoes from fish schools, complicate the process of classifying targets of naval interest. Specifically, small, dense patches of fish (fish schools) will “survive” an energy normalizer and appear “target-like”; large diffuse patches of fish will increase the threshold of detection. In addition, the prevalence of large patches of fish will increase the propagation loss, hence limiting detection range. The US Navy and NATO have conducted and plan to continue conducting naval exercises in the Black Sea, a biologically intense region where the effects of biological organisms on the performance of naval sonars are unknown. There are no reported measurements at mid frequencies of VSS, BA, target strength of fish schools, or geo-acoustic properties of the bottom in the Black Sea. We propose to apply novel instruments that permit concurrent measurement of VSS, BA and TS at the resonance frequencies of dispersed anchovies and schools of anchovies (nominally 1 to 5 kHz), the dominant species of fish in the Black Sea. To confirm the validity of inferences from bio-spectroscopy measurements, we will collaborate with fisheries scientists from the Middle East Technical University, Institute for Marine Science, who will provide biological truth (fish length distributions), derived from trawls. To eliminate bottom-related biases in inferences from bio-spectroscopy measurements, we will provide ground truth by conducting concurrent measurements of the geo-acoustic properties of the bottom. The proposed research will, for the first time, result in concurrent measurements at mid frequencies of VSS, BA of fish and TS of fish schools and the geo-acoustic properties of the bottom. The resultant measurements are expected to provide the experimental basis for predicting the performance of naval tactical sonars and development of tactics in the Black Sea. The proposed technical approach is also expected to provide a blueprint for the measurement and characterization of the bio-acoustic environment in other biologically intense regions of high naval interest. This proposal is a collaborative effort between Johns Hopkins University Applied Physics Laboratory (Orest Diachok), the Naval Research Laboratory (Altan Turgut), and the Woods Hole Oceanographic Institution (Tim Stanton and Cynthia Sellers). Identical proposals are being submitted by each institution for the research described in this document, but with separate budgets for the respective institutions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512045
Entities
People
- Orest Diachok
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy