Improvements in the Computation of Deflections of the Vertical by FFT

详细信息    查看全文

• 作者：Tziavos ; I. N. ; Andritsanos ; V. D.
• 刊名：Physics and Chemistry of the Earth
• 出版年：1998
• 出版时间：1998
• 年：1998
• 卷：23
• 期：1
• 页码：71-75
• 全文大小：327 K

文摘

Deflections of the vertical are computed by the effective FFT method using the Vening Meinesz integral formula in spherical convolution form. The gravimetric deflection components are compared with those derived by the planar FFT techniques as well as with observed astrogeodetic components in order to assess the improvements, in terms of accuracy, obtained by the spherical approximation. The use of the spherical two-dimensional (2D) FFT improves considerably the computational efficiency with little sacrifice of accuracy in comparison with the one-dimensional (1D) FFT results. Moreover, various tests are performed with respect to the different kernel functions used, while 100 % zero-padding is used in combination with discrete and analytical spectra in order to avoid the effect of circular convolution. Also discussed is the development of the software used in numerical tests, and ways of its further improvement by applying alternative formulations.