Modeling of multi-sensor tightly aided BDS triple-frequency precise point positioning and initial assessments
Modeling of multi-sensor tightly aided BDS triple-frequency precise point positioning and initial assessments
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DOI：
10.1016/j.inffus.2019.08.012
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
Zhouzheng Gao;M. Ge;You Li;Yuanjin Pan;Qijin Chen;Hongping Zhang
中科院分区：
文献类型：
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作者：
Zhouzheng Gao;M. Ge;You Li;Yuanjin Pan;Qijin Chen;Hongping Zhang
北斗全球导航卫星系统（BDS）是第一个为民用应用提供B1，B2和B3三频信号的卫星导航系统，已在亚太地区广泛应用。现有的北斗精密单点定位方法主要基于B1和B2双频观测值。为了充分利用北斗系统的三频观测值、运动传感器测量值和平台运动信息，提出了一种惯性传感器、里程计和航向测量紧密辅助的北斗三频PPP模型。在这个模型中，惯性传感器的偏差，里程表的比例因子，倾斜电离层延迟的残差，和频率间的代码偏差同时估计在一个独特的扩展卡尔曼滤波器。进一步采用RTS平滑器来降低解的噪声，提高解的稳定性和相对测量精度。为了评估该方法的能力，一组三频BDS原始观测，惯性测量，里程表数据，并通过定制的硬件系统在中国兰州-乌鲁木齐高速铁路轨道上收集的航向测量，处理和分析。结果表明，在北斗PPP中应用B3频率观测值，定位精度和周跳探测能力都得到了显著提高。利用B3观测、惯性传感器和RTS平滑器可以提高定位精度13-55%，利用航向测量可以提高航向精度70%以上。此外，这样的多传感器紧密集成系统可以直接提供毫米级的定位精度的重复性和提供亚毫米级的精度通过转换的姿态解决方案到距离的解决方案间接。这样的精度比最先进的GNSS高得多，并且这样的方法在3D几何测量中呈现出潜在的能力。
The BeiDou global navigation satellite system (BDS), which is the first satellite navigation system that provides triple-frequency signals on B1, B2, and B3 for civil applications, has been applied widely around the Asian-Pacifica region. The current BDS precise point positioning (PPP) approaches are mainly based on the B1&B2 dual-frequency observations. To make full use of BDS’ triple-frequency observations, the motion sensors measurements, and the platform motion information, this paper proposes an inertial sensor, odometer, and heading measurement tightly aided BDS triple-frequency PPP model. In this model, inertial sensor biases, odometer scale factor, residuals of slant ionospheric delays, and inter-frequency code biases are estimated simultaneously in a unique extended Kalman filter. The Rauch-Tung-Striebel (RTS) smoother is further adopted to reduce the solution's noises and enhance the stability and relative measuring accuracy. To evaluate the capability of this method, a set of triple-frequency BDS raw observations, inertial measurements, odometer data, and heading measurements collected by a customized hardware system on Lanzhou-Urumqi high speed railway track in China, are processed and analyzed. Results illustrated that both positioning accuracy and cycle slip detection capability are upgraded significantly by applying B3 frequency observations in BDS PPP. About 13–55% position accuracy enhancements from B3 observations, inertial sensors, and RTS smoother, and over 70% heading improvements from the aids of heading measurements can be obtained. Moreover, such multi-sensor tight integration system can directly provide millimeter-level positioning accuracy in term of repeatability and provide sub-millimeter-level accuracy indirectly by transforming attitude solutions into distance solutions. Such accuracy is much higher than the state-of-art GNSS and such method presents potential capability in 3D geometry measuring.