Application of Gaussian Overbounding on Ionospheric Error Analysis for China SBAS

摘要

Delay errors will follow a biased distribution under the ionospheric anomaly or storms conditions, making it difficult to overbound effectively the delay errors with the estimated error bounds for SBAS. Gaussian-bounding theorem provides a way to test the effectiveness of ionospheric error bound estimate. With the theorem, various bound estimating methods and its overbounding capability were analyzed with observations during storms for China area where ionospheric anomaly persists. It also shows the strength of different estimations, in which the irregularity detector is an integral component to minimize the size of bound while maintaining the effectiveness, bound estimate with dynamic inflation factor out¬performs over that of static inflating in system availability, and the undersampled threat model improves integrity margin in the bound at the cost of system avail¬ability, so diverse threat models are proposed to be constructed based on the ionospheric activities.