电离层闪烁对BDS区域系统定位性能的影响分析

The Influence of Ionospheric Scintillation on BDS's Positioning Accuracy

当电离层闪烁幅度衰落足够深,持续时间足够长时,用户接收机接收穿过电离层闪烁区域的卫星信号时其码和载波相位跟踪环路会失锁,导致这些卫星不可用,用户定位几何布局发生变化,进而影响定位性能。从GDOP退化、可用性、恶劣函数三个角度详细分析了电离层闪烁对BDS区域系统星座定位性能的影响。结果表明:存在电离层闪烁时,GDOP存在一定程度的退化,电离层闪烁中心点对应的地面位置GDOP退化程度最大,以此为中心向外辐射;可用性会下降,不过程度很小;恶劣函数值与电离层闪烁中心有关,且电离层闪烁中心越靠近目标点,影响越恶劣,当电离层闪烁中心远离目标点时,对定位影响几乎可以忽略。

When the decline of ionospheric scintiliation is deep enough and long enough, the signal will not exist. That will lead to some satellites unavailable and code tracking loop out of lock. For users, the acailable satellite geormetry layout changes, thereby affecting the positioning performance. I use BDS region measured data to analyse the influence of iono- spheric scintillation on positioning accuracy from GDOP degradation, availability and poor function. The results show that the presence of ionospheric scintillation,GDOP there is a cer- tain degree of degradation, ionospheric scinitillation largest center ground position corre- sponding to the degree of degradation GDOP, as the center outward radiation. Availablity will declin,but to a small extent. Bad {unction calue and ionospheric scintillation center concerned and ionospheric scintillation closer to the center target point,the more severe effects of iono- spheric scintillation center when away from the target point, the positioning of the impact is almost negligible.