A recently developed statistical model for first-order scattered fields is used to predict
the normalized covariance function of an underwater acoustic signal backscattered by a
hypothetical school of fish. The fish school is configured as an oblate spheroid with the
individual fish Poisson distributed within the school.
Empirical covariance functions...
An experimental underwater acoustic imaging system has been
designed and built. Operating at 650 KHz, real time acoustic images
are obtainable. Using both geometrical optics and Fourier optics,
the theory of image formation and resolution is presented. Other
factors affecting image quality and system acuity are also discussed.
System components...
Development of new research tools is needed to better understand the potential effects of a noisier ocean on individual and populations of marine mammals. Current behavioral response studies utilize ship-mounted sound sources to induce short-term noise-related behavioral responses in tagged animals. Combining the tag with the sound source into an...
From January 1980 to January 1981 approximate monthly sampling of a unique rockfish (Scorpaenidae) fishing area on Heceta Bank, Oregon was undertaken using acoustic techniques and trawling aboard chartered commercial fishing vessels. Rankings of density of fish sign observed on acoustic transects were regressed against selected environmental variables. Acoustic abundance...
Passive hydrophone technologies and a variety of acoustic methods are applied in
the deep-ocean and shallow water coastal environments of the northeast Pacific. A
catalog derived from U.S. Navy regional hydrophone array recordings of acoustic T- phases from seafloor earthquakes is examined, describing space/time patterns through
empirical orthogonal function analysis...
The effects of Marine protected areas (MPAs) on adult fish populations depend on the degree of protection provided, which is partly a function of MPA size and the spatial extent of fish movements. The Redfish Rocks Marine Reserve (RRMR) and MPA, located on the south coast of Oregon near Port...
