Research on ionospheric plasma bubbles affecting GLS operation with SBAS information-assisted monitoring

GLS is facing ionospheric delay anomalies that may lead to positioning errors exceeding the safety threshold, thereby threatening flight safety. SBAS usually uses ionospheric delay correction models to help users correct errors, but whether its data can be further used to monitor ionospheric threats still needs further research. This article uses multi-resolution ionospheric tomography technology and the Kriging method to statistically analyze the vertical delay difference between adjacent grid points in the low latitude region of China where ionospheric plasma bubbles appeared on February 21, 2021. The aim is to investigate whether SBAS ionospheric grid information can assist GLS in monitoring large spatial gradients. The research results indicate that when a certain grid is relatively close to the airport location and the edge of the ionospheric anomaly area, the absolute delay difference between the four grid points in the grid is greater than a certain threshold. It is judged that there is a large spatial gradient in this grid area, achieving the auxiliary effect of SBAS ionospheric grid information.