Improving the stochastic model for code pseudorange observations from Android smartphones

Research output: Contribution to journalArticleResearchpeer review

Authors

  • Berkay Bahadur
  • Steffen Schön

Research Organisations

External Research Organisations

  • Hacettepe University
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Details

Original languageEnglish
Article number148
Number of pages17
JournalGPS solutions
Volume28
Issue number3
Early online date25 Jun 2024
Publication statusPublished - Jul 2024

Abstract

In recent years, there has been increasing attention to positioning, navigation, and timing applications with smartphones. Because of frequently disrupted carrier phase observations, code observations remain critical for smartphone-based positioning. Considering a realistic stochastic model is mandatory to obtain the utmost positioning performance, this study proposes a sound stochastic approach for code observations from Android smartphones. The proposed approach includes a modified version of the SIGMA-ɛ variance model with different coefficients for each GNSS constellation and a robust Kalman filter method. First the noise characteristics of observations from the Xiaomi Mi 8 smartphone are analyzed utilizing code-minus-phase combinations to estimate the coefficients for each GNSS constellation. This includes the determination of a variance model as well as a check of the probability distribution. Finally, the proposed approach is validated in the positioning domain using single-frequency code observation-based real-time standalone positioning. The results show that more than 95% of observations follow the normal distribution when the proposed approach is applied. Compared with the conventional stochastic approach, including a C/N0-dependent model and standard Kalman filter, it improves the positioning accuracy by 45.8% in a static experiment, while its improvement is equal to 26.6% in a kinematic experiment. For the static and kinematic experiments, in 50% of the epochs, the 3D positioning errors are smaller than 3.0 m and 3.4 m for the proposed stochastic approach. The results exhibit that the stochastic properties of code observations from smartphones can be successfully represented by the proposed approach.

Keywords

    GNSS, Positioning, Robust Kalman filter, Smartphone, Stochastic model

ASJC Scopus subject areas

Cite this

Improving the stochastic model for code pseudorange observations from Android smartphones. / Bahadur, Berkay; Schön, Steffen.
In: GPS solutions, Vol. 28, No. 3, 148, 07.2024.

Research output: Contribution to journalArticleResearchpeer review

Bahadur B, Schön S. Improving the stochastic model for code pseudorange observations from Android smartphones. GPS solutions. 2024 Jul;28(3):148. Epub 2024 Jun 25. doi: 10.1007/s10291-024-01690-y
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