广义应变花方法及其在川滇地区地应变率场计算中的应用

General Strain Rosette Method and its Application to the Computation of Geo-Strain Rate in Chinese Sichuan-Yunnan Area

提出将工程测量中的平面应变花分析方法推广到地球球面上的广义应变花方法 ;并通过对已知位移和应变场的特例下的数值实验 ,比较常用的最小二乘配置法和广义应变花方法计算应变的精度 .结果显示广义应变花法应变的计算精度比最小二乘配置法高 .最后以中国川滇地区为例 ,利用GPS观测资料计算了地应变率场 ,并对计算方法和结果进行了分析讨论 .

GPS (global positioning system) velocity can be used to calculate the horizontal strain rate, but it should be done with great care because digital differentiation is involved, which brings about a prominent problem in minimizing the error. In this paper,a general strain rosette method (GSRM) is proposed, in which the plane strain rosette method in engineering is widened to include spherical earth surface. Then the GSRM is compared with the least squares collocation method (LSCM) in specific case by a digital experiment in which displacements and the strain field are known. The result shows that the accuracy of strain rate computed by GSRM is higher than that of LSRM. Finally, with Chinese Sichuan-Yunnan area as an example,the strain rate is calculated by GPS data and some discussions of computation methods and results are made.