Abstract: To analyze the no-modeling system error of orbit residuals in COMPASS, the orbit residuals feature extraction method with the ensemble empirical mode decomposition (EEMD) and Hilbert spectrum was proposed, and the normal distribution character of the orbit residuals chi-square test was analyzed. Firstly, the feature extraction principle of EEMD and Hilbert spectrum was introduced, the EEMD method assisted by the filter was proposed, and the feature extraction model of orbit residuals was established. Secondly, the feature of Pseudo-range and carrier phase orbit residuals in COMPASS was analyzed. Finally, the EEMD and Hilbert spectrum method was applied to analyze the Beidou GEO satellite orbit residuals. The results show that EEMD and Hilbert method can accurately extract the features of 1 day period, which is related to Beidou orbit running period. The chi-square value of the post orbit residuals obtained by EEMD is 5.5, which is smaller than the critical value of chi-square test. It proves that the post orbit residuals are normal distribution. The proposed method is important for separating the no-modeling system error in Beidou navigation satellite orbit residuals to improve the orbit determination precision.

Key words: font-size: 10pt, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-fareast-font-family: 宋体" lang="EN-US">Orbit residuals, Feature extraction, Distribution test, Pseudo-range, Carrier phase, Ensemble empirical mode decomposition, COMPASS