Calculation of the DAC curve for images reconstructed by digital aperture focusing method

The widespread introduction of antenna arrays into the practice of ultrasonic testing has made it possible to obtain images of reflectors using either phased array technology or digital aperture focusing (DFA) technology. However, many current regulatory documents regulating the rules for conducting ultrasonic non-destructive testing in the nuclear power industry, petrochemistry, gas industry, etc., require determining the equivalent dimensions of reflectors. The article proposes a method for calculating the DAF—DAC array to determine the diameter of an equivalent flat-bottomed hole (FBH) when analyzing an image. It was shown that it is more efficient to work not with the amplitude of the image, but with the integral amplitude. Numerical experiments have shown the accuracy of determining the diameter of the FBH of the order of ± 0.1 mm. In model experiments, the accuracy of determining the diameter of the FBH turned out to be modulo less than 0.2 mm.