INTERPRETATION TECHNIQUE FOR OBLIQUE LAYERED MEDIUM——THE RAYPATH TECHNIQUE
Yang Henai Yang Beifen
Based on the propagation rule of the refraction wave in the oblique layered medium, the refraction time-distance equation for multi-layered oblique interfaces was established. According to the following basic parameters: the intercept time of the refraction time-distance curve of each refractor, the apparent velocities corresponding to each curve and the wave-velocity in the first layer, the ray-paths of the down-going, the alongside-interface (in high-velocity medium), and the up-going refraction in layered medium could be automatically calculated and plotted by micro-computer with the recursive technique. In interpretation, the direct determination of the position and the occurrence of each refractor by the ray-path of the alongside-interface refraction is called THE RAY-PATH TECHNIQUE. Because of the raypath and its direction in each layer could be calculated with the technique recommended, it thus lays a foundation for the study of the dynamic characteristic of refraction in its propagation in theory. Based on the refraction time-distance equation for the oblique layered medium and with the aid of the raypath technique, the forward and the inverse calculation have been made for models of 4 and 5 layers. The charts concerned and the integrated flowchart were presented. Good results have been achieved from model experiments. It shows that the theory of the technique is right and proper and the way for its implementation is perfectly feasible.