均值漂移模型在地壳运动异常测站剔除中的应用

地壳运动及形变分析时，一般认为块体运动以刚性运动为主，整体具有长期稳定性。但受块体局部构造运动和观测粗差影响，少数测站会出现异常运动，只有剔除这些异常测站才能获得对研究区域地壳的长期运动趋势及运动规律的合理分析结果。长期以来，在进行测站筛选时，大多采用将残差标准差的验后估计与残差相比是否超过某一限值来判别异常测站，做法不具备检测粗差的能力，对异常测站剔除并不充分。本文提出利用均值漂移模型对异常测站进行剔除，并与拟准检定法及传统基于残差标准差的简单LS估计法进行对比；对中国大陆构造环境监测网络在环渤海区域的近几期GPS观测的速度场数据进行拟合分析。结果表明，通过均值漂移量求解的迭代过程，不仅能起到抗差测站筛选的作用，而且与拟准检定法相比，还能避免拟准观测选择不准确造成的影响，从而获得更高速度场拟合精度。

Application of mean shift model in anomalous station detection of crustal deformation analysis

In the analysis of crustal movement and deformation, it is generally believed that mass movement is featured by rigid motion, and the status of the block is considered as remarkably stable. However, due to local tectonic movement of the block and the gross error, abnormal movement will be observed from a few survey station. Only by removing these abnormal stations can the reasonable analysis results of the long-term movement trend and motion law of the crust in the study area be obtained. For a long time, the most common way to screen station is to see if the difference value between the posterior estimate of the residual standard deviation and residual error is beyond some limiting value. This method fails to eliminate abnormal stations efficiently. This paper proposes to use the mean shift model to eliminate the anomaly stations, and compare it with the quasi calibration method and the traditional residual-standard-deviation-based simple LS estimation method. The fitting analysis result of the recent velocity field data of GPS observation of China’s tectonic environment monitoring network in the Circum-Bohai-sea area shows that the iterative processusing the mean drift amount can not only screen the stations robustly, but also avoid the impact raised by selection inaccuracy of Quasi-Accurate-Observationand is able to obtain a higher velocity field fitting accuracy compared with the quasi-calibration method.