caa a22 4500 477047084 CHVBK 20180405111333.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00882061 doi (NATIONALLICENCE)springer-10.1007/BF00882061 Computation of additional components of the first-order ray approximation in isotropic media [Elektronische Daten] [Leo Eisner, Ivan Pšenčík] This study shows that the use of the first-order additional components of the ray method in the seismic wave field modeling is easy and that it can bring a substantial improvement of the standard ray results obtained with the zero-order ray approximation only. For the calculation of a first-order additional component, spatial derivatives of the parameters of the medium and spatial derivatives of the zero-order ray amplitude term are necessary. The evaluation of the former derivatives is straightforward; the latter derivatives can be calculated approximately from neighboring rays by substituting the derivatives by finite differences. This allows an effective calculation of the first-order additional terms in arbitrary laterally varying layered media. The importance of the first-order additional terms is demonstrated by the study of individual higher-order terms of the ray series representing elementaryP andS elastodynamic Green functions for a homogeneous isotropic medium. The study shows clearly that the consideration of the first-order additional terms leads to a more substantial decrease of the difference between approximate and exact elementary Green functions than any other higher-order term. With this in mind, effects of the first-order additional terms on the ray synthetic seismograms for aVSP configuration are studied. It is shown that the use of the additional terms leads to such phenomena, unknown in the zero-order approximation of the ray method, like quasi-elliptical and transverse polarization of a singleP wave or longitudinal polarization of a singleS wave. Birkhäuser Verlag, 1996 Ray series nationallicence first-order additional terms nationallicence Green function nationallicence Eisner Leo California Institute of Technology, Seismolab. 252-21, 91125, Pasadena, CA, USA aut Pšenčík Ivan Geophysical Institute, Acad. Sci. of Czech Republic, Boční II, Praha 4, Czech Republic aut pure and applied geophysics Birkhäuser-Verlag 148/1-2(1996-03-01), 227-253 0033-4553 148:1-2<227 1996 148 24 https://doi.org/10.1007/BF00882061 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00882061 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Eisner Leo California Institute of Technology, Seismolab. 252-21, 91125, Pasadena, CA, USA aut NATIONALLICENCE 700 1- Pšenčík Ivan Geophysical Institute, Acad. Sci. of Czech Republic, Boční II, Praha 4, Czech Republic aut NATIONALLICENCE 773 0- pure and applied geophysics Birkhäuser-Verlag 148/1-2(1996-03-01), 227-253 0033-4553 148:1-2<227 1996 148 24 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer