Phase Redundant Acoustical Holographyfor Noise Source Identification

摘要

In holography the image is observed by accumulating all complex waves reconstructed from hologram. Therefore we don't pay attention to how each complex wave works to reconstruct thernimage. If arbitrary image point is very sound source, almost all waves would be reconstructed with nearly the same phase. If the point is far away from sound source, each wave will be done with quite a different phase. Image resolution can be improved by considering how much phase distributes at thernimage point This paper introduces a new technology, called phase redundant holography, which successfully performs image reconstruction. A two-step procedure is used to perform this task. First, the conventional method is used to obtain the complex amplitude of the reconstructed image andrndetermine the phase of the final reconstruction. Each reconstructed phase is then compared with the final phase and the phase redundancy is multiplied by the reconstructed image. The phase redundancy is related to entropy of a reconstructed point’s phase information. The phase entropy is determined by considering both the conventional final image’s phase component and the exact opposite one. The resulting image has the same phase as the conventional method, but is different in amplitude. The proposed method, which utilizes a one-dimensional model, exhibits a noticeable improvement in noisernsource identification.