The performance of a nonlinear polarity thresholding algorithm was evaluated for coherent noise suppression in ultrasonic signals when the signal-to-noise ratio of the input signal was greater than unity. Probability of false alarm, probability of detection, and the receiver operating characteristics of the algorithm were developed so that its applicability to a given situation can be assessed before utilizing the technique. The algorithm introduces spurious high frequency contents to the grain noise amplitude and thereby motivates a low frequency bandpass filtering of the output signal to further reduce the coherent noise content of the signal. The results indicate that it is not necessary for the target signal amplitude to be larger than the noise level for an effective implementation of split spectrum processing.
|Original language||English (US)|
|Title of host publication||Review of Progress in Quantitative Nondestructive Evaluation|
|Number of pages||10|
|State||Published - 1988|
All Science Journal Classification (ASJC) codes