Elimination of distortions such as saturation of the ultrasonic echo signal by the least squares method and the Gershberg-Papulis method

When conducting ultrasonic testing, a situation may arise when the values of the recorded echo signals will be greater than the dynamic range of the receiving amplifier and the analog-to-digital converter of the flaw detector. This will cause the echo signals of pulses of large amplitude to undergo a cut-off operation (clipping) and reduce their amplitude, which may lead to an error when estimating the size of the reflector. A declipping method based on the Gershberg algorithm is proposed―Papulis, and its comparison with the declipping method using the least squares method is carried out. Numerical and model experiments have shown that the Gershberg method―Papulisa works more steadily than the least squares method for noisy echo signals and in the case of a rough step of their sampling.