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Full-Text Articles in Physical Sciences and Mathematics
Use Of Phase And Amplitude Gradient Estimation For Acoustic Source Characterization And Localization, Joseph Scott Lawrence
Use Of Phase And Amplitude Gradient Estimation For Acoustic Source Characterization And Localization, Joseph Scott Lawrence
Theses and Dissertations
Energy-based acoustic quantities provide vital information about acoustic fields and the characterization of acoustic sources. Recently, the phase and amplitude gradient estimator (PAGE) method has been developed to reduce error and extend bandwidth of energy-based quantity estimates. To inform uses and applications of the method, analytical and experimental characterizations of the method are presented. Analytical PAGE method bias errors are compared with those of traditional estimation for two- and three-microphone one-dimensional probes. For a monopole field when phase unwrapping is possible, zero bias error is achieved for active intensity using three-microphone PAGE and for specific acoustic impedance using two-microphone PAGE. …
Acoustic Intensity Of Narrowband Signals In Free-Field Environments, Kelli Fredrickson Succo
Acoustic Intensity Of Narrowband Signals In Free-Field Environments, Kelli Fredrickson Succo
Theses and Dissertations
The phase and amplitude gradient estimator (PAGE) method has proven successful in improving the accuracy of measured energy quantities over the p-p method, which has traditionally been used, in several applications. One advantage of the PAGE method is the use of phase unwrapping, which allows for increased measurement bandwidth above the spatial Nyquist frequency. However, phase unwrapping works best for broadband sources in free-field environments with high coherence. Narrowband sources often do not have coherent phase information over a sufficient bandwidth for a phase unwrapping algorithm to unwrap properly. In fact, phase unwrapping processing can cause significant error when there …
Energy Quantity Estimation In Radiated Acoustic Fields, Eric B. Whiting
Energy Quantity Estimation In Radiated Acoustic Fields, Eric B. Whiting
Theses and Dissertations
Energy quantities, which are calculated from pressure and particle velocity, yield a great deal of information about acoustic fields. Errors in pressure or particle velocity estimation lead to bias errors the estimation of energy quantities. The bias errors arise from different probe configurations and processing methods. Two processing methods are examined: the traditional method and the recently developed Phase and Amplitude Gradient Estimation (PAGE) method. These two methods are compared to investigate how each estimates pressure and particle velocity and the subsequent bias errors in a plane wave, standing wave, and spherical spreading wave field. Analytical expressions are derived for …
Investigation Of A New Method Of Estimating Acoustic Intensity And Its Application To Rocket Noise, Benjamin Young Christensen
Investigation Of A New Method Of Estimating Acoustic Intensity And Its Application To Rocket Noise, Benjamin Young Christensen
Theses and Dissertations
An alternative pressure-sensor based method for estimating the acoustic intensity, the phase and amplitude gradient estimation (PAGE) method, is presented. This method is similar to the finite-difference p-p (FD) method, in which the intensity is estimated from pressure measurements made using an array of closely spaced microphones. The PAGE method uses the same hardware as the FD method, but does not suffer from the frequency-dependent bias inherent to the FD method. Detailed derivations of the new method and the traditional FD method are presented. Both methods are then compared using two acoustic fields: a plane wave and a three monopole …