Multi-GNSS Differential Inter-System Bias Estimation for Smartphone RTK Positioning: Feasibility Analysis and Performance
Multi-GNSS Differential Inter-System Bias Estimation for Smartphone RTK Positioning: Feasibility Analysis and Performance
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DOI：
10.3390/rs15061476
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发表时间：
2023-03
期刊：
影响因子：
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通讯作者：
Rui Shang;Chengfa Gao;Lu Gan;Ruicheng Zhang;Wang Gao;Xiaolin Meng
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文献类型：
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作者：
Rui Shang;Chengfa Gao;Lu Gan;Ruicheng Zhang;Wang Gao;Xiaolin Meng
针对多个全球导航卫星系统(GNSS)的系统间模型使得不同GNSS星座之间的互操作性成为可能。近年来，大地测量接收机的系统间模型得到了广泛的研究。然而，智能手机的精确定位受到各种问题的困扰，目前的研究主要集中在如何实现GNSS模糊度的求解上。本文在研究接收端通道依赖偏差的基础上，研究了系统间偏差的时间行为，并实现了智能手机的系统间偏差模型。实验使用了一款具有代表性的华为P40(HP40)智能手机，实验结果表明：(1)对于HP40，码分多址(CDMA)系统的频率不存在与接收机信道相关的相位偏差，这为这些系统之间的进一步互操作提供了机会。然而，HP40的代码观测值受接收机通道依赖的代码偏差的影响；因此，建议在定位时为代码观测值设置较大的初始标准差(STD)值。(2)GPSL1/QZSSL1和BDS-2B1I/BDS-3B1I不存在DISB相，GPSL1和GALILEO E1之间存在明显的DISB相，即使如此，估值也是足够稳定的，标准差接近0.005个周期。然而，GPS L1/BDS B1I的DISB是不稳定的。(3)对于动态定位，引入稳定相位DISB后，系统间差分的定位精度在N/E/U方向上比系统内差分提高3~38.9%。
An inter-system model for multi-GNSSs (global navigation satellite systems) makes the interoperability among different GNSS constellations possible. In recent years, inter-system models for geodetic receivers have been extensively studied. However, the precise positioning of smartphones suffers from various problems, and the current research mostly focuses on how to achieve the GNSS ambiguity resolution. Based on the research of receiver channel-dependent bias, in this study, we will research the temporal behaviors of differential inter-system bias (DISB) and implement an inter-system model for smartphones. A representative Huawei P40 (HP40) smartphone was used in the experiments, and the results show the following: (1) For the HP40, the frequencies of Code Division Multiple Access (CDMA) systems are free of receiver channel-dependent phase bias, which provides the chances for further interoperability among these systems. However, the code observations of the HP40 are influenced by receiver channel-dependent code bias; it is therefore suggested to set a large initial standard deviation (STD) value for code observations in the positioning. (2) GPS L1/QZSS L1 and BDS-2 B1I /BDS-3 B1I are free of phase DISB, and there is obvious phase DISB between GPS L1 and Galileo E1; even so, the valuations are sufficiently stable and the STD is close to 0.005 cycles. However, the phase DISB of GPS L1/BDS B1I is unstable. (3) For kinematic positioning, when the stable phase DISB is introduced, a 3–38.9% improvement in the N/E/U directions of the positioning accuracies in the inter-system differencing is achieved compared with the intra-system differencing.