Recently, a phased-array probe is widespread also in an industrial field. However, it is not suitable for the inspection to the depth. The WMR method is an algorithm of making to visible of an internal structure. It uses the wavelet function for the sampling function and the image is reconstructed from the travel time and the attenuation of the transmission ultrasonic between two probes. However, when the difference between the number of sampling points and the measurement data grows, the reconstruction becomes difficult. In this paper, a triangular sampling is applied, and the number of specimens is decreased so the difference with the number of measurement data is reduced. As a result, the singular value decomposition is made easy to solve, and the accuracy of the reconstruction is improved. In addition, it proposes the reconstruction method by the structure of layered dividing area reconstruction using the scaling property. The number of sampling points is reduced further by changing the sampling interval. The reconstruction accuracy and the processing time are evaluated by the simulation and the effectiveness is shown. Moreover, the detection of the population defect is evaluated from acquired data by using the developed counting system.
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