摘要
针对卫星钟差数据中会经常出现粗差等数据异常的问题,该文提出了一种基于改进的中位数(MAD)方法的北斗卫星钟差数据预处理策略。该策略首先对长时间段卫星钟差数据的非空数据进行提取,然后将提取的非空数据转换为对应的频率数据,用改进的MAD方法进行处理,在此基础上再对长时间段的卫星钟差数据基于每天的数据采用改进的MAD方法进行再次预处理。通过对北斗卫星1a钟差数据的预处理,从钟差序列本身及其对应的频率序列和钟差的拟合残差3个方面对所提预处理策略进行了验证。实验表明,此策略能够有效地识别并处理北斗卫星钟差数据中的异常值。
Aiming at the problems of abnormal values such as gross errors which are inevitable to frequently occur in the satellite clock bias(SCB)data,this paper proposed a data preprocessing strategy for BeiDou navigation satellite system(BDS)SCB based on an improved median absolute deviation(MAD)method.Specifically,nonempty data was extracted firstly from the original long-time SCB sequence to be preprocessed using the improved MAD method,the subsequent step was to preprocess again the daily data of the preprocessed SCB data based on the improved MAD method.Using the proposed process preprocessing one-year BDS SCB data,the new process was validated from aspects of the preprocessed SCB sequences and corresponding frequency sequences and the fitting residuals of SCB data.The validated results showed that this process could effectively recognize and deal with abnormal values in the BDS SCB data.
引文
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