Statistical Flaw Detection: Theory

In this paper we discuss the problem of flaw detection using ultrasound. We describe the decision theoretic optimal algorithm for interior flaw detection in the presence of noise. Based on this algorithm, an efficient sub-optimal algorithm is derived that can be implemented in real time. Finally, we present some results of computer simulation tests comparing the new algorithm with a more traditional video detection scheme based on peak waveform thresholding. Preliminary evaluation of the new detection scheme under laboratory experimental conditions is described in a companion paper [Elsley, Fertig, and Richardson (1983)]. We first start with a brief statement of the specific detection problem we are addressing.