Impact of New GPS Signals on Positioning Accuracy for Urban Bus Operations
Impact of New GPS Signals on Positioning Accuracy for Urban Bus Operations
复制标题
新GPS信号对城市公交运营定位精度的影响
作者：
Mireille Elhajj;W. Ochieng
本文首次以公交车运行为例，分析了新型GPS信号对动态城市应用定位精度的影响。性能评估包括代码测量精度和定位精度。前者是基于信噪比和多径和噪声的估计，由码和载波相位测量相结合。通过比较传统的单频GPS定位相对于参考轨迹的性能，得出了对定位精度的影响，这两种定位都是通过将载波相位测量数据与高级惯性测量单元的数据集成来实现的。结果表明，L5码的测量精度最高，其次是L1 C/A和L2C码。在定位领域，与单频测量相比，双频编码测量在二维和三维精度上有显著提高，分别提高39%和48%，从而支持更多的公交运营服务。
This paper analyses for the first time the impact of new GPS signals on positioning accuracy for dynamic urban applications, taking bus operations as an example. The performance assessment addresses both code measurement precision and positioning accuracy. The former is based on signal-to-noise ratio and estimation of multipath and noise by a combination of code and carrier phase measurements. The impact on positioning accuracy is derived by comparing the performance achievable with the conventional single frequency GPS only positioning both relative to reference trajectories from the integration of carrier phase measurements with data from a high grade inertial measurement unit. The results show that L5 code measurements have the highest precision, followed by L1 C/A and L2C. In the positioning domain, there is a significant improvement in two-dimensional and three-dimensional accuracy from dual frequency code measurements over the single frequency measurements, of 39% and 48% respectively, enabling more bus operation services to be supported.