Abstract This paper analyzes the error characteristics of high-rate single-epoch GPS time series and uses the median filtering method to eliminate the high rate noise. Through calculation we determine that the accidental error in the horizontal direction is ±4.0-4.5 mm and in the elevation direction it is ±9 mm. By periodically repeating solutions, comparing the time series, and maximizing the correlation coefficient, the periodic system error is discovered in the high-rate single-epoch GPS time series. The repetition period is from 86 153 to 86 165 seconds. Through modeling or differencing the system errors, the system components can be eliminated from the time series, thus improving the data processing accuracy of high-rate single-epoch GPS.