排序方式: 共有12条查询结果,搜索用时 15 毫秒
11.
P.?VajdaEmail author A.?Ellmann B.?Meurers P.?Vaní?ek P.?Novák R.?Tenzer 《Studia Geophysica et Geodaetica》2008,52(1):35-52
Compilation of the bathymetrically and topographically corrected gravity disturbance, the so called BT disturbance, for the
purpose of gravity interpretation/inversion, is investigated from the numerical point of view, with special emphasis on regions
of negative heights. In regions of negative ellipsoidal (geodetic) heights, such as the Dead Sea region onshore or offshore
areas of negative geoidal heights, two issues complicate the compilation and subsequently the inversion of the BT disturbance.
The first is associated with the evaluation of normal gravity below the surface of the reference ellipsoid (RE). The latter
is tied to the legitimacy of the harmonic continuation of the BT disturbance in these regions. These two issues are proposed
to be resolved by the so called reference quasi-ellipsoid (RQE) approach. New bathymetric and topographic corrections are
derived based on the RQE and the inverse problem is formulated based on the RQE. The RQE approach enables the computation
of normal gravity by means of the international gravity formula, and makes the harmonic continuation in the regions of negative
heights of gravity stations legitimate. The gravimetric inversion is then transformed from the RQE approach back to the RE
approach, following the now legitimate harmonic upward continuation of the gravity data to stations on or above the RE. Stripping,
the removal of an effect of a known density contrast, is considered in the context of the RQE approach. A numerical case study
is presented for the RQE approach in a region of NW Canada. 相似文献
12.
Far-zone gravity field contributions corrected for the effect of topography by means of molodensky’s truncation coefficients 总被引:1,自引:0,他引:1
Robert Tenzer Pavel Novák Peter Vajda Artu Ellmann Ahmed Abdalla 《Studia Geophysica et Geodaetica》2011,55(1):55-71
A spectral representation of the topographic corrections to gravity field quantities is formulated in terms of spherical height
functions. When computing the far-zone contributions to the topographic corrections, various types of the truncation coefficients
are applied to a spectral representation of Newton’s integral. In this study we utilise Molodensky’s truncation coefficients
in deriving the expressions for the far-zone contributions to topographic corrections. The expressions for computing the far-zone
gravity field contributions corrected for the effect of topography are then obtained by combining the expressions for the
far-zone contributions to the gravity field quantities and to the respective topographic corrections, both expressed in terms
of Molodensky’s truncation coefficients. The numerical examples of the far-zone contributions to the topographic corrections
and to the topography-corrected gravity field quantities are given over the study area situated in the Canadian Rocky Mountains
with adjacent planes. Coefficients of the global elevation and geopotential models are used as the input data. 相似文献