Abstract
Non-destructive inspection by the electromagnetic wave (Radar) conventionally makes use of the shaded images on the magnitude variation of the reflected waves, i. e., B-mode images, and anomaly diagnosis has been qualitatively done with inspector's eye. This yielded the diagnosis of low reliability and low accuracy.
The paper proposes two diagnosis methods of high reliability and high accuracy based on the received signal obtained as a time-series. One is the method which evaluates the similarity of the peak pattern of the received signal with a standard one when the radar is crossed over an iron bar. Another is the one which evaluates the symmetricity and the continuity of the peak pattern. By the peak pattern meant is the location of “mountains and valleys" of the received signal, where the mountains and valleys represent respectively the relative maxima and minima of the received signal.
