基于原始观测值的UWB增强GNSS精密单点定位方法研究

UWB enhanced GNSS precise point positioning based on raw measurements

关键词:  精密单点定位  超宽带  收敛时间  传感器融合  锚点数目

Key words:  Precise point positioning  Ultra-wideband  Convergence time  Sensor fusion  Anchor number

摘要:

全球卫星导航系统(global navigation satellite system, GNSS)可提供全球范围内全天候高精度导航、定位和授时服务。以精密单点定位(precise point positioning, PPP)为代表的绝对定位技术凭借定位精度高且全球一致、作业范围灵活等优势受到广泛关注，但是较长的收敛时间，限制了其在实时、快速精密定位应用中的使用。为解决上述问题，提出了超宽带(ultra-wideband, UWB)增强PPP方法，在多星座PPP中紧密集成UWB测距信息，以提高GNSS PPP性能。实验结果表明，在动态场景下，融合UWB量测使GPS/GAL双系统PPP在东、北、天３个方向的位置均方根(root mean square,RMS)值分别减少了76.99%、21.46%、64.53%，ＧＰＳ/GAL/BDS三系统PPP减少了69.69%、37.21%、61.32%，并且收敛时间分别加快62.78%和57.75%。关于锚点数（几何构型）的评估表明，仅利用4个锚点就能将双系统和三系统3D误差RMS值减少67.98%、59.35%，收敛时间加快76.14%、62.68%，达到成本和性能综合最优的增强效果。

Abstract:

Global satellite navigation system(GNSS) can provide all-round and high-precision navigation, positioning and timing services around the world. Absolute positioning technology represented by precise point positioning(PPP) has attracted widespread attention due to its advantages of high accuracy, global consistency and flexible operating range. But the long convergence time limits its use in real-time and fast precision positioning applications. In order to solve the problems, an ultra-wideband(UWB) enhanced ＰＰＰ method is proposed, which tightly integrates UWB and PPP to improve the positioning accuracy. The experimental results show that in the dynamic scenario, the proposed method reduces the root mean square(RMS) values of the PPP result of the GPS/GAL system by 76.99%, 21.46%，64.53%, and the GPS/GAL/BDS sytems by 69.69%, 37.21% and 61.32%,in east, north and up directions,with their convergence time being shortened by 62.78% and 57.75%, respectively. The evaluation of anchor points number, which also represents geometric configuration, shows that the RMS values of the 3D error of the GPS/GAL and GPS/GAL/BDS systems can be reduced by 67.98% and 59.35%, and the convergence time can be shortened by 76.14% and 62.68% with only 4 anchors, so as to achieve the enhancement effect of the best comprehensive cost and performance.