Thesis (M.S.)--University of MIichigan, 1958.

No description available.

No description available.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 96-101).

Acoustic methods have long been used to rapidly and synoptically survey marine organisms of ecological and economic importance. Direct sampling furnishes biological data such as abundance, biomass, direct measurements of organism size and species identification, but encounters problems such as net avoidance, small sampling volumes, and catch destruction of delicate specimens. Understanding the scattering mechanisms of fish is challenge due to the fact that fish anatomy is complex and the acoustic scattering characteristics are correspondingly complex. For example, (Nash,1987) qualitatively illustrated the influence of the various anatomical components of fish on scattering by performing length-wise acoustic scans of whole fish, dissected swimbladders. The swimbladder is the main control factor of fish¡¦s floating and diving. This research will carry on the measure the target with acoustic characteristic of imitative air swimbladder of Tsuchida Seisakusho. We use the imitative air swimbladder and collocate the Reversed Engineering to measure the Backscattering intensity of the swimbldder which is different medium. We set up experiment in an acoustic water tank of dimension (4mo3.5mo2m) located in National Sun Yat-sen University. The projector and receiver both are transducer of fish finder with directivity and frequency response at 200k Hz. The signal receptor used Data Acquisition System of NI 6129 with sample rate at 800kHz. The target set up of this research is referring to (Timothy K. Stanton,2004), and we use servo motor to control the incidence angle of the target. Preliminary research is pointed out, the target strength will change by the incidence geometry of the target, and the target diameter is the factor of the target strength.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 75-80).

Thesis (Ph. D. in Oceanography)--University of California, San Diego, 2001. / Includes bibliographical references. Also available online.

No description available.

A very interesting effect in light propagation through a disordered system is Anderson localization of light, this phenomenon emerges as the result of multiple scattering of waves by electric inhomogeneities like spatial variations of index of refraction; as the amount of scattering is increased, light propagation is converted from quasi-diffusive to exponentially localized, with photons confined in a limited spatial region characterized by a fundamental quantity known as localization length. Light localization is strongly related to another interference phenomenon emerged from the multiple scattering effect: the coherent backscattering effect. In multiple scattering of waves, in fact, coherence is preserved in the backscattering direction and produces a reinforcement of the field flux originating an observable peak in the backscattered intensity, known as backscattering cone. The study of this peak provide quantitative information about the transport properties of light in the material. In this thesis we report a complete FDTD ab-initio study of light localization and coherent backscattering. In particular, we consider a supercontinuum pulse impinging on a sample composed of randomly positioned scatterers. We study coherent backscattering by averaging over several realizations of the sample properties. We study then the coherent backscattering cone properties as the relative permittivity of the sample is changed, relating the latter with the light localization inside the sample. We demonstrate important relationships between the width of the backscattering cone and the localization length, which shows a linear proportionality in the strong localization regime.

This work describes the design, implementation, and calibration of NOAA's coherent, pulsed, Doppler lidar. This lidar was used to acquire 252 high quality, independent measurements of atmospheric backscattering profiles from 4 to 30 km altitude over Boulder, Colorado, at a wavelength of 10.6 micrometers between May 1981 and May 1983, a period that includes the injection and removal of debris from the El Chichon eruptions. Statistical analyses of the data set by computer show that atmospheric backscattering is approximately lognormally distributed for all but the lowest altitudes, and a theoretical explanation is offered for this property. Seasonally-averaged profiles and altitudinally-stacked, filtered time sequences show the volcanic cloud appearing in the stratosphere and falling through the tropopause into the troposphere at rates far higher than can be explained by gravitational settling alone. The dynamic process of tropopause folding is proposed as the dominant mechanism for the observed exchange of volcanic debris from the stratosphere to the troposphere. This hypothesis is supported by case studies of mid-tropospheric backscatter-enhancing events. Mie calculations and comparisons with other measurements show that vertically-integrated backscatter is a good long-term measure of total atmospheric mass loading of volcanic debris. It is found that the time constant which characterizes debris removal is 208 days for the stratosphere and 60 days for the troposphere. No appreciable debris is removed before the volcanic cloud falls to 6 km altitude 420 days after the volcanic eruptions.