少星环境下的矢量跟踪接收机增强技术研究

Enchantment of Vector Tracking Loop Performance Under Signal Challenging Environments

卫星导航系统已经成为最常用的导航和定位手段,地面车辆、智能手机等都依靠卫星导航接收机提供高精度导航和定位信息。然而在城市复杂环境下,卫星导航信号常常被环境遮挡,接收机接收不到足够数量的卫星信号,导致接收机定位误差变大或者不能输出导航信息。矢量跟踪接收机采用卡尔曼滤波估计导航定位信息,能够在少星环境下提供一定精度的定位信息,但是误差随着时间发散。为了提高矢量跟踪接收机在少星环境下的性能,提出高度信息辅助矢量跟踪接收机方法,给出了高度信息辅助下矢量接收机导航信息估计模型。实际场景实验表明,在2 min的实验时间中,采用高度信息辅助,定位精度有了明显的提升。

Global Navigation Satellite System(GNSS)has become the most popular apparatus for generating navigation and positioning informationand ground vehiclessmartphones et al all rely on GNSS for obtaining high-precision navigation and positioning information.Howeverunder complex city environmentsGNSS signals are often blocked by the surroundingsand thus the GNSS receiver can't obtain adequate signalswhich may lead to big positioning errors or no output of navigation solutions.Vector Tracking Loops(VTL)use a Kalman filter to estimate the navigation and positioning solutionsand VTL is able to output positioning information with only one visible satellite.Howeverthe positioning errors will diverge over time.In order to improve the VTL performance under signal challenging environmentsthis paper proposes an altitude information aided VTL methodand the model is given.Field tests show that the positioning errors are obviously reduced in the two-minute experiment with the aid of altitude information.