一种北斗二代卫星钟差的数据质量控制方法

A Data Quality Control Method for the Beidou-2 Satellite Clock Bias

考虑北斗二代卫星长期钟差序列中存在的钟跳、粗差及数据缺失现象,提出一种钟差序列的数据质量控制方法。利用频率序列识别钟跳,采用阈值法进行异常数据段剔除以及结合MAD和Baarda数据探测法共同进行粗差探测与剔除,再利用线性内插对缺失数据进行插补,得到干净的钟差序列。实测数据表明,这种钟差质量控制策略可以显著提高北斗钟差序列信息提取的准确性以及钟差预报精度。

To improve the predictive accuracy of Beidou satellite clock bias （SCB）, it is necessary to a dopt a proper method of data quality control to preprocess SCB. The phenomena consisting of phase jumps, outliers, and missing data exist in long term Beidou SCB sequence. Considering all these fac- tors, a data quality control method for the Beidou-2 SCB series is proposed. The method is as follows. First, identify clock jumps through frequency sequence. Next, use threshold to get rid of abnormal data segments and combine median absolute deviation （MAD） and Baarda to detect and delete outli- ers. Then, replace missing points with linearly interpolated values. Finally, a clean SCB sequence is achieved. Based on the use of measured Beidou-2 SCB data,the test results show that the quality control strategy of clock bias can significantly improve the accuracy of real information extracted from Beidou-2 SCB and prediction.