An Improved Ionospheric Spatial Threat Model for SBAS
An Improved Ionospheric Spatial Threat Model for SBAS
复制标题
改进的 SBAS 电离层空间威胁模型
DOI：
10.1049/cje.2017.07.002
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发表时间：
2017-09
影响因子：
1.2
通讯作者：
Zhipeng Wang
中科院分区：
文献类型：
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作者：
Qidong Zhang;Rui Li;Zhipeng Wang
保守的网格电离层垂直延迟误差（GIVE）估计会导致保守的保护水平（PL）估计，并影响星基增强系统（SBAS）的服务性能。为了减小GIVE估计中的误差，提出了一种改进的空间威胁模型.引入了一个新的参数最小间隔距离（MSD）。新模型以MSD、相对质心度量（RCM）和拟合半径作为输入。在风暴期间的电离层延迟测量被用来构建新的空间威胁模型。仿真结果表明，新模型在用户电离层延迟估计误差有界的同时，用户电离层垂直延迟误差至少减少了9.5%。即使在严重的电离层干扰天，至少5%的PL（95%）的改善可以实现超过20%的美国本土（CONUS）地区，导致更高的系统服务性能。
A conservative Grid ionospheric vertical delay error (GIVE) estimation would lead to conservative Protection levels (PLs) estimation and affects Satellitebased augmentation systems (SBAS) service performance. To reduce the margin in GIVE estimation, an improved spatial threat model is presented. A new parameter ofMinimum separation distance (MSD) is introduced. The new model is described with the MSD, Relative centroid metric (RCM) and fit radius as inputs. Ionospheric delay measurements during storms are used to construct the new spatial threat model. Simulation results show that, with the new model, there is at least 9.5% reduction in User ionospheric vertical delay errors (UIVEs), while the user ionospheric delay estimation errors can be bounded at the same time. Even on severe ionosphere disturbed days, at least 5% improvement of PLs (95%) could be achieved for more than 20% Conterminous united states (CONUS) area, leading to higher system service performance.