Ionospheric Threat Model Methodology for WAAS
Ionospheric Threat Model Methodology for WAAS
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DOI：
10.1002/j.2161-4296.2002.tb00259.x
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发表时间：
2002-06
影响因子：
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通讯作者：
J. Blanch;T. Walter;P. Enge
中科院分区：
文献类型：
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作者：
J. Blanch;T. Walter;P. Enge
：电离层是影响 GPS 的最大剩余误差源。它还具有一些最不可预测的空间和时间变化。因此，电离层成为广域增强系统（WAAS）系统性能的决定因素。由于无法同时在所有位置观测到电离层，因此只能借助威胁模型来确定置信界限（称为网格电离层垂直误差 (GIVE)）。威胁模型用于限制预期的电离层行为。需要一种方法来准确描述威胁模型的局限性，但又不会过于悲观。本文描述了一种使用真实数据生成最坏情况场景的方法，从中可以确定适当的威胁模型。该威胁模型必须与一组可以区分观察良好的电离层区域的指标相结合。
: The ionosphere is the largest remaining error source affecting GPS. It also has some of the least predictable spatial and temporal variations. Consequently, the ionosphere becomes the determining factor in system performance for the Wide Area Augmentation System (WAAS). Because the ionosphere cannot be observed at all places simultaneously, the confidence bound, termed the grid ionospheric vertical error (GIVE), can be determined only with the aid of a threat model. The threat model is used to restrict the expected ionospheric behavior. A method is needed for accurately describing the limits of the threat model without being overly pessimistic. This paper describes a methodology for using real data to generate worst-case scenarios from which an appropriate threat model can be determined. This threat model must be coupled with a set of metrics that can distinguish well-observed ionospheric regions.