Influence of Pitch of Ultrasonic Antenna Array on Efficiency of Extraction of a Signal from Structural Noise in Flaw Detection

Abstract

The question of selecting the pitch of an ultrasonic antenna arrays in order to obtain the maximal signalto-structural noise ratio is considered. The ordinary mode of a linear antenna array, in which one of its elements radiates a signal and the other receives a signal, as well as the synthetic aperture mode, and the SAFT-C mode, in which each element in turn radiates a signal and the others receive the signal, are described. It is shown that the SAFT-C mode produces a four-fold increase in the signal-to-structural noise ratio from that achieved in the other modes.