An analytical raypath approach to the refraction wavefront method
M. Ali Ak
Journal name: Geophysical Prospecting
Issue: Vol 38, No 8, November 1990 pp. 971 - 982
Info: Article, PDF ( 441.58Kb )
Seismic refraction surveying is still an important tool for determining the geometries and elastic wave propagation velocities of near-surface layers. Many analytical and graphical methods have been developed over the years for refraction interpretation, and these can be classified into two basic groups. The first group visualizes critically refracted rays converging on a common surface position, while the second group, which includes the wavefront methods, makes use of the critical rays emerging from a common point on the refractor.
The method described in this paper is an analytical approach to the wavefront methods. The reverse refracted ray received by a geophone is intersected by the forward refracted rays received by subsequent geophones and a common critical refraction point on the refractor is estimated after a series of comparisons. This process is repeated for each geophone to yield the geometry and the velocity of the refractor. Several interpolations are performed to achieve a better accuracy.
Palmer's models are used to test the efficiency of the algorithm. The results are presented together with those of other methods applied to the same models.