High Resolution Refraction Data Acquisition And Interpretation

Refraction and reflection seismic methods are named for a key element of<br>the geometry of the ray paths in each method, respectively. Both methods are<br>affected by the refraction of seismic rays at velocity contrast boundaries.<br>However, the key geometrical element in the reflection method is that the rays<br>incident on a target boundary are reflected back to the surface. In refraction<br>surveying, the incident ray is critically refracted along the target<br>boundary before it returns to the surface. Refraction seismic methods were<br>employed in the petroleum industry before the reflection methods were develaped,<br>and the same evolution has been seen in the shallow-target application<br>of the seismic methods.