基于零基线数据对北斗导航系统观测噪声的评估

Evaluation of the Observation Noise of the Beidou Satellite Navigation System Based on the Zero Baseline Data

北斗导航系统中接收到的各频段各个类型的观测数据,特别是载波相位观测值质量的好坏,将直接影响北斗系统的定位精度。因此,本文研究基于科廷大学零基线观测数据,采用无几何无电离层组合方法,首次分别对北斗系统伪距各个观测类型,载波相位各个观测类型及不同类型卫星的噪声进行了全面细致的评估。实测数据证明:对于北斗系统,不同的伪距观测类型,噪声可能变化很大,但其中至少有一种伪距观测类型的噪声小于0.1 m;MEO和IGSO卫星具有相似的载波相位噪声水平,但GEO卫星的噪声大小与仰角明显相关,随着仰角的减小,噪声会随之增加。

In the Beidou satellite navigation system,the received observation data of each type of each frequency band,especially the quality of the carrier phase observation value,will directly affect the positioning accuracy of the Beidou system. Therefore,based on the zero baseline observation data of Curtin University,this paper uses the geometry-free and ionosphere-free combination method to evaluate the noise of each observation type of the Beidou system pseudo-range,the carrier phase,and the noise of different types of satellites. It is verified by the measured data: For the Beidou system,the noise can vary greatly for different pseudo-range measurement types and there is at least one pseudo-range measurement type in each system with noise smaller than 0.1 m;MEO and IGSO have similar level of carrier phase noise,but noise of GEO is clearly related to elevation angle,with the decrease of elevation angle,the noise increases.