caa a22 4500 477046940 CHVBK 20180405111332.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF00874581 doi (NATIONALLICENCE)springer-10.1007/BF00874581 Point source radiation in inhomogeneous anisotropic structures [Elektronische Daten] [Ivan Pšenčík, Telesson Neves Teles] The ray formulae for the radiation from point sources in unbounded inhomogeneous isotropic as well as anisotropic media consist of two factors. The first one depends fully on the type and orientation of the source and on the parameters of the medium at the source. We call this factor the directivity function. The second factor depends on the parameters of the medium surrounding the source and this factor is the well-known geometrical spreading. The displacement vector and the radiation pattern defined as a modulus of the amplitude of the displacement vector measured on a unit sphere around the source are both proportional to the ratio of the directivity function and the geometrical spreading. For several reasons it is desirable to separate the two mentioned factors. For example, there are methods in exploration seismics, which separate the effects of the geometrical spreading from the observed wave field (so-called true amplitude concept) and thus require the proposed separation. The separation also has an important impact on computer time savings in modeling seismic wave fields generated by point sources by the ray method. For a given position in a given model, it is sufficient to calculate the geometrical spreading only once. A multitude of various types of point sources with a different orientation can then be calculated at negligible additional cost. In numerical examples we show the effects of anisotropy on the geometrical spreading, the directivity and the radiation pattern. Ray synthetic seismograms due to a point source positioned in an anisotropic medium are also presented and compared with seismograms for an isotropic medium. Birkhäuser Verlag, 1996 Inhomogeneous anisotropic media nationallicence point sources nationallicence the ray Green function nationallicence the directivity function nationallicence the radiation pattern nationallicence ray synthetic seismograms nationallicence Pšenčík Ivan Geophysical Institute, Academy of Sciences of Czech Republic, Boční II, 4, Praha, Czech Republic aut Neves Teles Telesson PPPG, Universidade Federal da Bahia, Rua Caetano Moura 123, Federação, 40.210.350, Salvador, Brazil aut pure and applied geophysics Birkhäuser-Verlag 148/3-4(1996-09-01), 591-623 0033-4553 148:3-4<591 1996 148 24 https://doi.org/10.1007/BF00874581 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00874581 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Pšenčík Ivan Geophysical Institute, Academy of Sciences of Czech Republic, Boční II, 4, Praha, Czech Republic aut NATIONALLICENCE 700 1- Neves Teles Telesson PPPG, Universidade Federal da Bahia, Rua Caetano Moura 123, Federação, 40.210.350, Salvador, Brazil aut NATIONALLICENCE 773 0- pure and applied geophysics Birkhäuser-Verlag 148/3-4(1996-09-01), 591-623 0033-4553 148:3-4<591 1996 148 24 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer