Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Android multi-GNSS ambiguity resolution in the case of receiver channel-dependent phase biases
https://orcid.org/0000-0002-8776-5801
Abstract The availability of GNSS raw measurements and the improved performance of mass-market GNSS chipsets for tracking multi-constellation dual-frequency signals have facilitated the development of smartphone high-precision GNSS positioning. However, the channel-dependent carrier phase biases within typical smartphone GNSS chipset prevent Android multi-GNSS ambiguity resolution. In this study, the channel-dependent biases were investigated for the Android GLONASS G1, BDS B1I, Galileo E5a and QZSS L1 carrier phase observations. They destroy the integer property of GNSS ambiguities and result in varying GLONASS inter-frequency bias (IFB) rates. As a result, Android multi-GNSS double-difference ambiguity resolution is hindered and the traditional method of correcting for a constant GLONASS IFB rate is no longer applicable. We propose an on-the-fly phase biases correction method, which introduces reliability verification by resolving only the bias-free ambiguities and estimating the phase bias corrections on-the-fly by gain filtering. In this way, GPS/GLONASS/Galileo/BDS/QZSS dual-frequency ambiguities are resolved for a representative Xiaomi Mi 8 smartphone. For a ~ 13 km short baseline, when the smartphone is connected to an external survey-grade antenna, the time to first fix was 50 s and the fixing rate was 99.21% with the root mean square (RMS) of positioning errors of 1.32, 1.48 and 1.92 cm for the east, north and up components, respectively. Compared with dual-frequency GPS and five-constellation GNSS without phase biases correction, the ambiguity-fixing rate was improved by 30.4% and 99.2%, and the positioning accuracy was improved by 93.4% and 41.8%, respectively. In the case of the smartphone’s embedded antenna, the ambiguity-fixing rate of five-constellation GNSS dropped to about 60% due to multipath, but the positioning precision of its ambiguity-fixed solutions was still at centimeter level, which was less than one-tenth of its float solutions. Therefore, the implementation of multi-GNSS ambiguity resolution will further boost the potential of high-precision GNSS positioning for smartphones.
Android multi-GNSS ambiguity resolution in the case of receiver channel-dependent phase biases
https://orcid.org/0000-0002-8776-5801
Abstract The availability of GNSS raw measurements and the improved performance of mass-market GNSS chipsets for tracking multi-constellation dual-frequency signals have facilitated the development of smartphone high-precision GNSS positioning. However, the channel-dependent carrier phase biases within typical smartphone GNSS chipset prevent Android multi-GNSS ambiguity resolution. In this study, the channel-dependent biases were investigated for the Android GLONASS G1, BDS B1I, Galileo E5a and QZSS L1 carrier phase observations. They destroy the integer property of GNSS ambiguities and result in varying GLONASS inter-frequency bias (IFB) rates. As a result, Android multi-GNSS double-difference ambiguity resolution is hindered and the traditional method of correcting for a constant GLONASS IFB rate is no longer applicable. We propose an on-the-fly phase biases correction method, which introduces reliability verification by resolving only the bias-free ambiguities and estimating the phase bias corrections on-the-fly by gain filtering. In this way, GPS/GLONASS/Galileo/BDS/QZSS dual-frequency ambiguities are resolved for a representative Xiaomi Mi 8 smartphone. For a ~ 13 km short baseline, when the smartphone is connected to an external survey-grade antenna, the time to first fix was 50 s and the fixing rate was 99.21% with the root mean square (RMS) of positioning errors of 1.32, 1.48 and 1.92 cm for the east, north and up components, respectively. Compared with dual-frequency GPS and five-constellation GNSS without phase biases correction, the ambiguity-fixing rate was improved by 30.4% and 99.2%, and the positioning accuracy was improved by 93.4% and 41.8%, respectively. In the case of the smartphone’s embedded antenna, the ambiguity-fixing rate of five-constellation GNSS dropped to about 60% due to multipath, but the positioning precision of its ambiguity-fixed solutions was still at centimeter level, which was less than one-tenth of its float solutions. Therefore, the implementation of multi-GNSS ambiguity resolution will further boost the potential of high-precision GNSS positioning for smartphones.
Android multi-GNSS ambiguity resolution in the case of receiver channel-dependent phase biases
https://orcid.org/0000-0002-8776-5801
Abstract The availability of GNSS raw measurements and the improved performance of mass-market GNSS chipsets for tracking multi-constellation dual-frequency signals have facilitated the development of smartphone high-precision GNSS positioning. However, the channel-dependent carrier phase biases within typical smartphone GNSS chipset prevent Android multi-GNSS ambiguity resolution. In this study, the channel-dependent biases were investigated for the Android GLONASS G1, BDS B1I, Galileo E5a and QZSS L1 carrier phase observations. They destroy the integer property of GNSS ambiguities and result in varying GLONASS inter-frequency bias (IFB) rates. As a result, Android multi-GNSS double-difference ambiguity resolution is hindered and the traditional method of correcting for a constant GLONASS IFB rate is no longer applicable. We propose an on-the-fly phase biases correction method, which introduces reliability verification by resolving only the bias-free ambiguities and estimating the phase bias corrections on-the-fly by gain filtering. In this way, GPS/GLONASS/Galileo/BDS/QZSS dual-frequency ambiguities are resolved for a representative Xiaomi Mi 8 smartphone. For a ~ 13 km short baseline, when the smartphone is connected to an external survey-grade antenna, the time to first fix was 50 s and the fixing rate was 99.21% with the root mean square (RMS) of positioning errors of 1.32, 1.48 and 1.92 cm for the east, north and up components, respectively. Compared with dual-frequency GPS and five-constellation GNSS without phase biases correction, the ambiguity-fixing rate was improved by 30.4% and 99.2%, and the positioning accuracy was improved by 93.4% and 41.8%, respectively. In the case of the smartphone’s embedded antenna, the ambiguity-fixing rate of five-constellation GNSS dropped to about 60% due to multipath, but the positioning precision of its ambiguity-fixed solutions was still at centimeter level, which was less than one-tenth of its float solutions. Therefore, the implementation of multi-GNSS ambiguity resolution will further boost the potential of high-precision GNSS positioning for smartphones.
Android multi-GNSS ambiguity resolution in the case of receiver channel-dependent phase biases
Li, Guangcai (Autor:in) / Geng, Jianghui (Autor:in)
Journal of Geodesy ; 96
2022
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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