Exact Solution Of Seismo Grams By Earth Flattening Transformation

There is no exact solution of seismograms in the spherical coordinate system , and the numerical calculation consumes too much time. If we compute synthesis seismograms by generalized reflection-transmission coeffcient method(GRTCM) combined with earth flattening transformation, the problem can be solved. The first part of this paper derived the Similarityof the wave function in the spherically symmetric media and in layered media under some approximations , solved analytical solution of the eigenvalue the PSV coefficient matrix after flattening transform . The latter part gave lots of numerical results. The results show that the flattening transformation index n has little effect on the calculation results. In the case of small epicenter, the approximation is suitable. When the epicenter is greater than 3 degrees,less than 15 degrees the exact result and the approximation result are similar.