共查询到20条相似文献，搜索用时 31 毫秒
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Ray tracing in factorized anisotropic inhomogeneous media 总被引：1，自引：0，他引：1
V. &#;ervený 《Geophysical Journal International》1989,99(1):91-100
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Determination of the influence zone for surface wave paths 总被引：6，自引：1，他引：6
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Summary. A method of comparison of exact numerical computations with an asymptotic ray series expansion consisting of the two first terms is proposed. The method makes it unnecessary to derive complicated explicit expressions for the second leading term of the ray series.
As a practical example we consider the anomalous PS arrival generated in the case of a near-vertical incidence of a spherical P wave on a solid/solid boundary. The areas in which the PS wave may be described by two leading terms of the ray series expansion are marked and deviations from the ray theory are analysed. 相似文献
As a practical example we consider the anomalous PS arrival generated in the case of a near-vertical incidence of a spherical P wave on a solid/solid boundary. The areas in which the PS wave may be described by two leading terms of the ray series expansion are marked and deviations from the ray theory are analysed. 相似文献
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Ray tracing in random media 总被引：1，自引：0，他引：1
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Interpolation of ray theory traveltimes within ray cells 总被引：1，自引：0，他引：1
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Ray perturbation theory and the Born approximation 总被引：1，自引：0，他引：1
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Geocentre motion from the DORIS space system and laser data to the Lageos satellites: comparison with surface loading data 总被引：3，自引：0，他引：3
F. Bouillé A. Cazenave J. M. Lemoine J. F. Crétaux 《Geophysical Journal International》2000,143(1):71-82
Surface mass redistribution within the Earth system, especially in the atmosphere, oceans, continents and ice sheets, causes the position of the centre of mass to vary in a reference frame attached to the solid Earth. Space techniques are now precise enough to measure the centre of mass motion. Here we present a determination of the centre of mass coordinates at regular monthly intervals using DORIS data on SPOT‐2, SPOT‐3 and Topex–Poseidon (1993–1997) and laser data on Lageos‐1 and Lageos‐2 (1993–1996). The amplitude and phase of the space‐geodesy‐derived annual cycle for each coordinate are further compared to estimates based on surface mass redistribution at the Earth surface derived from various climatic data sources: surface pressure, soil moisture, snow depth and ocean mass variations. 相似文献
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Matthias Zillmer Boris Kashtan & Dirk Gajewski 《Geophysical Journal International》1998,132(3):643-653
Wave propagation in weakly anisotropic inhomogeneous media is studied by the quasi-isotropic approximation of ray theory. The approach is based on the ray-tracing and dynamic ray-tracing differential equations for an isotropic background medium. In addition, it requires the integration of a system of two complex coupled differential equations along the isotropic ray.
The interference of the qS waves is described by traveltime and polarization corrections of interacting isotropic S waves. For qP waves the approach leads to a correction of the traveltime of the P wave in the isotropic background medium.
Seismograms and particle-motion diagrams obtained from numerical computations are presented for models with different strengths of anisotropy.
The equivalence of the quasi-isotropic approximation and the quasi-shear-wave coupling theory is demonstrated. The quasi-isotropic approximation allows for a consideration of the limit from weak anisotropy to isotropy, especially in the case of qS waves, where the usual ray theory for anisotropic media fails. 相似文献
The interference of the qS waves is described by traveltime and polarization corrections of interacting isotropic S waves. For qP waves the approach leads to a correction of the traveltime of the P wave in the isotropic background medium.
Seismograms and particle-motion diagrams obtained from numerical computations are presented for models with different strengths of anisotropy.
The equivalence of the quasi-isotropic approximation and the quasi-shear-wave coupling theory is demonstrated. The quasi-isotropic approximation allows for a consideration of the limit from weak anisotropy to isotropy, especially in the case of qS waves, where the usual ray theory for anisotropic media fails. 相似文献