多GNSS监测下中国区域电离层格网模型可用性分析

Availability analysis for ionospheric gird model in China areas under multi-GNSS observations

多系统全球卫星导航系统(GNSS)的出现为天基增强系统(SBAS)电离层格网模型的性能提升提供了可能,但多系统GNSS测量对电离层格网模型性能提升是有条件的.为此,利用中国区域GPS观测模拟分析了多系统GNSS测量对中国区域电离层格网模型可用性的影响.结果表明:多系统GNSS测量可有效提高电离层格网模型的覆盖范围.中国南方地区存在低纬赤道电离异常(EIA)现象,严重影响SBAS电离层格网模型实现性能,单纯增加GNSS测量不能有效应对低纬电离异常现象影响.中国北方地区电离层延迟变化平缓,在多系统GNSS测量情况下可以考虑减少地面监测站数量,仍能保持系统原有性能.

While multi-Global Navigation Satellite System(GNSS)observation make it possible for a better performance of ionospheric model for Space Based Augmentation System(SBAS),the potential improvement depends on various factors.The paper analyzes the availability of ionospheric grid model for SBAS covering China and around areas under multi-GNSS scenarios.The results show that the covering area of grid model could be extended with multi-GNSS measurements.But for southern China,where equatorial ionolization anomaly(EIA)exists,the performance improves marginally as the increased observations cannot counter effectively the EIA's serious impacts on grid model.In northern China,the ionosphere varies smoothly and multi-GNSS observations are helpful to reduce the number of sites while maintains the system performance.