北斗三号电离层模型性能分析

根据北斗卫星导航系统三步走战略,北斗三号系统空中星座在2020年左右完成部署,信号的覆盖范围从亚太大部分地区扩展至全球.实际上自2018年底北斗三号系统已经可以初步提供全球服务.相应地,北斗系统的单频电离层模型从只适用于亚太大部分地区的BDSKlob模型发展到适用于全球范围的BDGIM模型.为分析北斗三号电离层模型的性能,以IGS GIM最终数据为参考,比较了2019年3月1-31日期间北斗BDGIM模型、BDSKlob模型以及GPSKlob模型在不同时段不同地区的改正效果.结果表明:北斗三号BDGIM模型在中国区域的改正率达75%以上,优于BDSKlob模型59%的改正率;在全球范围的改正率达60%,优于GPSKlob模型49%的改正率.除南半球高纬度地区外,BDGIM模型的电离层误差值均小于GPSKlob模型,其在垂直方向的电离层均方根误差值优于6 TECU.

Performance Analysis of BDS Single Frequency Ionosphere Model

With the construction of BDS-3, the single-frequency ionospheric model of BDS-2 (BDSKlob) which is only suitable for the correction of ionosphere delay in Chinese area is no more applicable. The BDGIM model is proposed for the correction of ionosphere delay globally in BDS-3. The performance of BDGIM model is compared with BDSKlob and GPSKlob (the ionospheric model of GPS) in different areas for day and night in the time period of 1-31 March 2019. The results show that the correction ratio of BDGIM model of BDS-3 is over 75% in China while that of BDSKlob is 59%. Its global correction ratio is 60% which is superior to the correction ratio 49% of GPSKlob. As far as the Root Mean Square (RMS) of ionosphere is concerned, the global average value of BDGIM model is less than that of GPSKlob. The RMS of vertical ionospheric error of BDGIM is less than 6 TECU in all the other areas excluding the high latitude area of south hemisphere.