Performance of GNSS Global Ionospheric Modeling augmented by LEO Constellation
Performance of GNSS Global Ionospheric Modeling augmented by LEO Constellation
复制标题
LEO 星座增强 GNSS 全球电离层建模的性能
DOI：
10.1029/2019ea000898
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发表时间：
2020
影响因子：
3.1
通讯作者：
Li Xingxing
中科院分区：
文献类型：
--
作者：
Ren Xiaodong;Zhang Xiaohong;Schmidt Michael;Zhao Zhibo;Chen Jun;Zhang Jincheng;Li Xingxing
低轨（LEO）卫星运动速度快，卫星几何分布变化快，可以有效地抑制多径效应，提供更多的观测数据。最近，一些研究已经调查了LEO增强的全球导航卫星系统（GNSS）定位和导航。然而，还没有关于低地球轨道增强全球电离层建模的研究。本文首次介绍了低轨星座增强的全球电离层模型的性能和精度。基于60、96和192颗卫星的3种LEO星座设计的仿真数据，结果表明LEO观测可以扩大覆盖范围，增加电离层穿透点（IPPs）密度。同时，随着LEO卫星数量的增加，IPP的密度变得更高。当截止仰角设置为40°时，GNSS+LEO的IPP分布仍然优于仅GNSS在10°时的IPP分布。通过这种方式，可以增加GNSS测量的截止仰角，因为映射函数误差和多径效应被减小。此外，全球电离层地图的性能进行了评估。基于观测的GNSS和GNSS+LEO方案。与仅GNSS相比，最小和最大偏差可以分别从-18.1总电子含量单位减少到-7.0总电子含量单位和从12.6总电子含量单位减少到6.4总电子含量单位，并且具有60、96和192颗卫星的LEO星座的均方根值分别提高了35.9%、46.5%和50%。
The Low‐Earth‐Orbiting (LEO) satellite has a fast motion and thus contributes to rapid changes in satellite geometric distribution, which can effectively mitigate multipath effects and offer more available observations. Recently, some studies have investigated LEO‐augmented Global Navigation Satellite System (GNSS) positioning and navigation. However, the study of LEO‐augmented global ionospheric modeling was not yet available. In this paper, we present the performance and accuracy of global ionospheric model augmented by LEO constellation for the first time. Based on the three kinds of designed LEO constellations with 60, 96, and 192 satellite simulation data, the results show that LEO observations can expand the coverage and increase the density of ionospheric pierce points (IPPs)..Meanwhile, the density of IPPs becomes higher with an increasing number of LEO satellites. When the.cutoff elevation is set to 40°, the IPP distribution of GNSS+LEO is still better than that of GNSS‐only at 10°..This way the cutoff elevation angle of the GNSS measurements can be increased, since the mapping function.error and the multipath effects are reduced. Furthermore, the performances of global ionosphere maps.based on the observations of GNSS‐only and GNSS+LEO scenarios are evaluated. Compared with.GNSS‐only, the minimum and maximum bias can be reduced from −18.1 to −7.0 total electron content unit.and from 12.6 to 6.4 total electron content unit, respectively, and the root‐mean‐square values with LEO.constellations of 60, 96, and 192 satellites improve by 35.9%, 46.5%, and 50%, respectively.