Transmission/Reflection Dual-Mode Ultrasonic Tomography Using Weighted Least Square-Lagrange Joint Reconstruction

Industrial ultrasonic tomography (UT) possesses unique advantages in multiphase medium imaging and has received broad attention. In this article, a novel transmission/reflection dual-mode image reconstruction algorithm based on information fusion is proposed. The transmissive attenuation and reflective time-delay information are both integrated into an improved Lagrange framework with the weighted least square transformation of objective function, which is then solved by a pair of coupled preconditioned gradient approaches. Experiment results show that the proposed algorithm performs better than existing image fusion strategies in terms of accuracy (average relative error 0.456, average correlation coefficient 0.870) and robustness (average standard derivation of relative error and correlation coefficient 0.056 and 0.041). Accordingly, the dual-mode UT approach is proved feasible to provide more accurate image of biphasic medium distribution.