The Shortest Path Ray Tracing Algorithm in Concrete Computerized Tomography

Algebraic reconstruction technique (ART) is widely used in concrete computerized tomography. The algorithm usually uses straight-line ray tracing, so the projection matrix will never change once the model is built. In order to improve the accuracy of ART and eliminate phenomena that the wave velocity of the units around anomalous body is far from the true value, The shortest path ray tracing (SPT) is introduced into ART and is modified. Before each iteration, the projection matrix is anew computed through using SPT ray tracing. After each iteration, the wave velocity of the normal units is smoothed. Computer simulation and concrete model of ultrasonic computerized tomography show that the combination of SPT ray tracing and ART is effective to control wave velocity dispersion and improve the accuracy of computation and the quality of image reconstruction on concrete.