Acta Geodaetica et Cartographica Sinica ›› 2021, Vol. 50 ›› Issue (4): 475-486.doi: 10.11947/j.AGCS.2021.20200258

• Geodesy and Navigation • Previous Articles     Next Articles

Variational mode decomposition method for estimation of GNSS data quality from a smartphone

PENG Zihan, GAO Chengfa, LIU Yongsheng, ZHANG Ruicheng, SHANG Rui   

  1. School of Transportation, Southeast University, Nanjing 211189, China
  • Received:2020-06-24 Revised:2021-02-05 Published:2021-04-28
  • Supported by:
    The National Natural Science Foundation of China (No. 41974030);The Indoor and Outdoor Integrated Fusion Positioning Algorithm Technical Support Service for Smartphone (No. 8521008666)

Abstract: At present, the third-derivative approach or the inter-epoch difference method is mainly used to calculate the GNSS observation noise of the smartphone, but the results of these approaches will be affected by satellite correlation and time correlation. Aimed to the GNSS data noise estimation of smartphones, we propose an approach of noise estimation method based onvariational mode decomposition (VMD). Firstly, it uses VMD to extract low-frequency components of double-difference observations, then inversely calculates the single-difference observations of each satellite, and finally calculates the observation noise of each satellite. Simulation decomposition experiments show that VMD can decompose mixed signals satisfactorily. The analysis results of the GNSS data quality from the Xiaomi 8 indicate that the pseudorange noise of GPS, BDS and Galileo are analogous. The pseudorange noise of GLONASS is about twice that of the other systems, and the phase noise of the four systems are coincident. Observation noise will not be influenced by the operating system. In addition, the carrier-to-noise ratio stochastic model is more suitable for GNSS positioning of smartphones than elevation stochastic model. Compared with the using of latter model, the single point positioning effect of smartphones can be improved by more than 25% after using the carrier-to-noise ratio model. The PPP results of the smartphone can converge to within 0.6 and 1.2 m in horizontal and vertical components, respectively.

Key words: smartphone GNSS, variational mode decomposition, quality analysis, stochastic model

CLC Number: