采用GPS差分改正数提高手机导航定位精度

Improving the Positioning Accuracy of Smartphone with GPS Differential Corrections

当前手机定位精度较低,大约在10 m量级。其原因除了手机跟踪信号精度较低外,还受电离层延迟、对流层延迟、卫星钟差、卫星轨道等误差的影响。针对手机定位精度较低以及人们对手机高精度定位的需求的问题,提出了一种采用差分改正数提高手机定位精度的算法。本算法采用单参考站GPS伪距差分改正数修正手机定位结果,并通过实验分析了三星S4和三星Note3通过本文算法修正后的定位精度改善效果。实验结果表明:在动态情况下,开阔区域利用单参考站改正数对手机定位精度可至少提高13%,当然手机内置芯片不同,提升效果有所差异。

The current smartphone is capable of locating the users with an accuracy of about 10 meters.For typical pseudor-ange-based smartphone positioning,the measurements are usually contaminated by atmospheric error,satellite orbit error, satellite clock error and cellphone internal noise.So it is significant for enhancing the positioning accuracy.By carrying out Dif-ferential GNSS(DGNSS)computation in the coordinate domain,the algorithm utilizes the pseudorange corrections to estimate the coordinate corrections,and applies the coordinate corrections to the initial coordinates obtained from the GNSS chipset in the smartphone.The field test demonstrates that the differential solution enhances the positioning accuracy by 13% in terms of 3D error,and the performances vary in different phones due to different chipset designs that give rise to model errors in the correction processing.