面向Android智能终端的多模GNSS实时非差精密定位

Android操作系统中全球导航卫星系统(GNSS)原始数据的开放为大众高精度位置服务的应用带来了重要机遇。在对Android系统GNSS原始数据特性分析的基础上,利用智能终端GNSS原始数据实现了实时非差精密定位,研制了面向Android平台的实时精密单点定位(PPP)软件PPPAnd,并开展了实际环境下的定位测试。测试结果表明:基于Android终端GNSS原始数据的实时静态伪距单点定位精度(RMS)为1.16m(水平方向)和1.51m(垂直方向),较其自身位置速度和时间(PVT)解算结果分别提高了70%和76%;实时静态精密单点定位解算结果的精度(RMS)为0.62m(水平方向)和0.66m(垂直方向),较PVT结果分别提高了87%和82%,精度收敛至1m以内所需时间约8min,并且收敛后的精度可达亚米级;城市环境中车载实时动态精密单点定位的水平和垂直精度(RMS)分别约为1.32m和0.81m,较PVT结果分别提高了39%和65%。

Multi-GNSS Real-time Un-differenced Precise Positioning for Android Smart Devices

The availability of GNSS raw measurements from mass-market smart devices with Android operator system opens the door to more advanced GNSS positioning techniques for high-precision location-based services. For the purpose of improving the positioning accuracy of smart devices, real-time un-differenced precise positioning with Android GNSS raw measurement is investigated in this paper. First, the basic characters of the Android GNSS measurements are analyzed. Following this, a real-time un-differenced precise positioning method with Android GNSS raw measurements is implemented, and a real-time precise point positioning (PPP) software called PPPAnd is developed based on the Android platform. Finally, the real-time positioning performance is validated with real data. Numerical results show that the RMS (root mean square) value of real-time single point positioning errors with Android raw GNSS measurement is 1.16m and 1.51m in the horizontal and vertical components, respectively; compared with the PVT (Position Velocity and Time) solutions of Android device, the improvements of accuracy are 70% for the horizontal component and 76% for the vertical component. For real-time precise point positioning in static mode, the positioning accuracies (RMS) in the horizontal and vertical components are 0.62m and 0.66m, respectively, with an improvement of 88% and 82% for the corresponding component compared with the PVT solutions. In addition, the required convergence time for the accuracy level of 1.0m is about 8min, and once it converged the positioning accuracy of static PPP can reach to sub-meter level. For the vehicle-based real-time kinematic precise point positioning in urban environment, the positioning accuracies are 1.32m in the horizontal component and 0.81m in the vertical component and the corresponding improvement of positioning accuracy relative to the PVT solutions is 39% and 65%, respectively.