Error analysis of strain rates from GPS measurements based on Monte Carlo method
基于Monte Carlo方法的由GPS观测计算地应变率的误差分析

The strain rate in Chinese continent has been computed from GPS data by many researchers, resulting in quite different estimates of the strain rates. Moreover, until now, researchers have not presented the errors of the strain rate yet, which are very important in geodynamics. In order to solve this problem, we propose a method to calculate the error of strain rate computed from GPS vectors with measurement errors on the base of Monte Carlo technique. Taken the Qinghai-Tibet plateau as an example, independent computation of strain rate is repeated for large numbers of times, and the components of strain rates, as well as the errors, are obtained by statistical theory. The result shows that the errors of strain rates in NS, EW directions and shear components are larger in Himalayas and in the middle and the east of the plateau than those in other places. In general, the strain rate in whole Qinghai-Tibet plateau is accurate and stable. Also the result suggests that the errors of the strain rates computed from GPS measurements are mainly originated from the errors of GPS data. The accuracy of GPS survey does not meet the requirements for precisely computing the strain rates in the region of small deformation, for example in east China.