Geometrical Acoustic Propagation with Frequency Dependence

Benthic Biota and High-Frequency Acoustic Propagation

We also targeted emergent fauna for manipulation, choosing elimination over enhancement as a more practical manipulation. Treatments consisted of smoothing 4-m2 plots by hand and covering them with black plastic weighed down by rebar to smother the underlying fauna. Paired controls included smoothing and rebar, but no plastic. After about 3 d, the plastic was removed to monitor the effects of r...

High Frequency Acoustic Channel Characterization for Propagation and Ambient Noise

Predicting underwater detection capabilities as well as vulnerabilities depends strongly on the characteristics of the ocean acoustic propagation channel. Operational advantages can be obtained by exploiting the ambient noise field to characterize the channel. The long term goal of this research is to determine methods that take advantage of the ambient noise field to extract useful information...

High Frequency Acoustic Propagation Studies and Thermal Microstructure

The specific goal of this program was to develop a non-invasive in-situ technique for the observation of thermal microstructure which was based upon the thermal dependence of the Raman scatter of light. The hypothesis that we sought to explore was whether our multispectral low-light-level color camera (LUMIS) could be used to image the Raman emission spectra in a way which would allow the infer...

Low Frequency Acoustic Intensity Propagation Modeling in Shallow Water Waveguides

High-frequency Acoustic Propagation in the Presence of Oceanographic Variability

Broadband mid-to-high frequency (0.6-18 kHz) acoustic wave propagation in shallow coastal waters (< 20 m) is influenced by a variety of oceanographic conditions. Physical parameters such as temperature and salinity as well as hydrodynamic parameters such as surface waves, tide and current can influence amplitude and travel time of signal transmissions. In this paper a unique set of simultaneous...