An extension of Frank's method for obtaining crustal shear strains from survey data
An extension of Frank's method for obtaining crustal shear strains from survey data
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发表时间：
1976-12
影响因子：
3
通讯作者：
W. Prescott
中科院分区：
文献类型：
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作者：
W. Prescott
本文将Frank 9的从三角形的角的重复观测中获得剪应变γ_1和γ_2的方法推广到处理任意角的集合和每个角的任意观测次数。这种修改使得有可能提高信噪比，从而检测较小幅度的应变场。假设应变率在测量数据所覆盖的时空范围内是恒定的，用应变率γ tec 1和γ tec 2代替剪应变分量γ 1和γ 2，并对观测值进行最小二乘平差，以确定γ tec 1和γ tec 2的最概然值。在利用各测站的全方差-协方差矩阵进行平差时，考虑了用舍入法观测到的相邻角的观测值之间的非零相关性。统计检验表明，该方法能正确估计γ stec 1和γ stec 2的离散度。
abstract Frank9s method of obtaining shear strains γ 1 and γ 2 from a repeated observation of the angles of a triangle has been generalized to deal with any collection of angles and an arbitrary number of surveys of each angle. This modification makes it possible to increase the signal-to-noise ratio and thus detect smaller magnitude strain fields. Under the assumption that the strain rate is constant over the space time covered by the survey data, the shear strain components γ 1 and γ 2 are replaced by their rates γ˙ 1 and γ˙ 2 , and a least-squares adjustment of the observations is used in determining most probable values of γ˙ 1 and γ˙ 2 . The nonzero correlation between observations of adjacent angles that have been observed by the method of rounds is taken into consideration in making the adjustment by using the full variance-covariance matrix at each station. Statistical testing of the method indicates that it correctly estimates the dispersion of γ˙ 1 and γ˙ 2 .