Preliminary Assessment of Improved Smartphone GNSS Quality Control Methods Based on Range Errors

Jiahuan Hu and Sunil Bisnath

Abstract: Global navigation satellite systems (GNSS) have undergone an evolution that has positively impacted user solution performance. For mass market smartphone GNSS applications, modernized GNSS brings in multi-constellation and multi-frequency signals, but also raises a challenge in dealing with the possibly problematic measurements. Understanding the smartphone range error characteristics in realistic environments allow users to improve smartphone GNSS measurement processing strategies. Hence, this paper focuses on utilizing the derived smartphone range errors in improving quality control methods in terms of a priori code precision, weighting schemes, and residual rejection. With 12 smartphone datasets collected in realistic driving environments, the range errors are first calculated and the positioning performance comparison is carried out. The 95th percentile horizontal positioning errors can be reduced by 0.5 m with more realistic code precision of 3.5 m compared to the empirical value of 1 m. Three weighting schemes are proposed and compared by fitting the correlation between range errors and signal-to-noise ratio (SNR) or elevation angle, and the positioning performance with the fitted weighting schemes are more stable than the conventional SNR-related weighting scheme, with an improvement of 0.6 m for the 95th percentile horizontal positioning errors. An adaptive posteriori residual rejection threshold function is established, and compared to a fixed threshold of 20 m, the adaptive threshold can have a centimeter-level improvement in horizontal positioning errors in realistic environments.
Published in: Proceedings of the 36th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2023)
September 11 - 15, 2023
Hyatt Regency Denver
Denver, Colorado
Pages: 85 - 98
Cite this article: Hu, Jiahuan, Bisnath, Sunil, "Preliminary Assessment of Improved Smartphone GNSS Quality Control Methods Based on Range Errors," Proceedings of the 36th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2023), Denver, Colorado, September 2023, pp. 85-98. https://doi.org/10.33012/2023.19206
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