An Improved Method for MAD Gross Error Detection of Clock Error

  Objectives  Satellite clock difference (SCB) is affected by many factors, such as data discontinu‍ity, jump and gross error, among which the gross error is the most representative. Traditional SCB gross error detection method is the median absolute deviation (MAD) method

  Methods  With the single difference of SCB as the research object, we analyzed the working principle of traditional MAD method. In view of the deficiency of traditional MAD in SCB gross error detection, an improved gross error detection method was proposed. Firstly, the ambiguity in mathematical expression was eliminated by optimizing the model structure, and then dynamic MAD was generated based on the basic principle of ridge regression, which effectively overcame the interference of some single difference data with significant trend changes on gross error detection.

  Results  We used International Global Navigation Satellite System Service precision SCB as reference for experiments. Compared with traditional MAD, the detection accuracy and recall rate of the proposed method were better than traditional MAD, especially for the data with obvious change of trend characteristics.

  Conclusions  The proposed method has obvious advantages in gross error detection accuracy and recall rate and has high application value.