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...
The feasibility of utilizing acoustic imaging techniques for
improving the undersea viewing capability of small submersibles is
investigated. The limiting values of major parameters in acoustic
imaging systems are established and graphs which illustrate the
parametric relationships are presented. A series of sample calculations
illustrate how the graphs can be...
Acoustic scanned holography is a method of lensless photography
which uses sound waves to construct the hologram and light waves to
reconstruct the image. The receiving transducer scans a plane area
containing the sound field generated or scattered from the objects. In
simultaneous source receiver scanning, both the source and...
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...
A procedure for displaying cursory computer analyses of time
series acoustic signals is described. The graphic presentation is
optimized for visual analysis. The results displayed represent time
series signals and/or Power Spectral Density estimates.
Both hardware and software components of the procedure are
described and compared with current methods. Suggestions...
The ability to interpret graphical information is a prime concern in physics as
graphs are widely used to give quick summaries of data sets, for pattern recognition, and for analysis of information. While visual graphs have been developed so that their content can be readily and concisely discerned, there is...
Applications of several methods of coherent nonlinear Raman Spectroscopy have been made in this thesis research. The theory and potential of one of these, Photoacoustic Raman Spectroscopy (PARS), is discussed in chapter two. Experimental results are presented which illustrate the sensitivity of this method and establish sampling conditions for maximum...
Pulsed ultra-wideband (UWB) radio uses extremely short pulses to transmit
information. Such pulses provide very fine timing information, which has led to
technological advances in high-precision localization. This thesis focuses on
techniques and experiments of Time-Difference-of-Arrival (TDOA) localization of
a large number of simultaneous sources. First, common localization techniques
such...
