oa Pseudo Three-Dimensional Refraction Method for Rock Bed Detection

Refraction tomography nowadays has developed to unveil 3 dimensional structures of subsurface. Delineation of a rock bed which usually happens to be one of the main purpose of a survey in most engineering sites, however, is not easy because inversions usually produce images of gradual change of the material properties. From the survey designed for 3 dimensional refraction data acquisition, we can get the contours of first arrivals of a shot on the surface by applying an interpolation such as kriging. Re-sampling first arrivals form these contours, we get reciprocal traveltime curves between two shots respectively. Then, we applied the generalized reciprocal method (Palmer, 1982) using these data finally to get a pseudo 3 dimensional subsurface structure.