Application of CF and DMAS Technology to Improve the Quality of Reflector Images Reconstructed from Echoes Measured by an Antenna Array

Abstract

The reliability and sensitivity of ultrasonic testing are determined by the noise level in the images of reflectors and their resolution. The application of CF or DMAS technologies in various combinations is promising, as these technologies are relatively simple, require minimal additional computational resources, and can be applied to echo signals measured by conventional flaw detectors operating with antenna arrays. Numerical and model experiments have demonstrated that the use of these methods allows for an increase in the resolution of the images of reflectors by more than two times and a reduction in noise level by more than 20 dB. In a numerical experiment, it was shown that phase distortions due to complex coefficients of refraction and reflection can cause the indication of the crack tip to shift from its true position by approximately one wavelength, even with precisely known experimental parameters when operating on a straight beam on a transverse wave. This represents a significant error for flaw detection tasks. However, if phase correction is applied during the reconstruction of the images of reflectors, then the indication of the crack tip aligns with its actual position. CF and DMAS technologies have demonstrated their effectiveness even when working with noisy echo signals.