SHAKING: Adjusted spherical harmonics adding KrigING method for near real-time ionospheric modeling with multi-GNSS observations. Issue 1 (1st January 2023)

• Record Type: Journal Article
• Authors: Liu, Ang; Li, Zishen; Wang, Ningbo; Zhang, Yan; Krankowski, Andrzej; Yuan, Hong
• Is Part Of: Advances in space research. Volume 71:Issue 1(2023)
• Page Start: 67
• Page End: 79
• Publication Date: 2023-01-01
• Subjects: Ionospheric TEC modeling -- Near real-time -- Adjusted spherical harmonics -- SHAKING; Space sciences -- Periodicals; Astronautics -- Periodicals; Geophysics -- Periodicals; 500.505
• DOI: 10.1016/j.asr.2022.07.049
• Languages: English
• ISSNs: 0273-1177

Abstract

Highlights: VTEC over the sparse observation data area is reasonably extrapolated by the Adjusted Spherical Harmonic (ASH). Boundary effect of spherical cap is eliminated by the stochastic component estimation with Kriging. Real-time Multi-GNSS (GPS, GLONASS and BDS-2/3) data streams are used in SHAKING-based solution. Abstract: Precise positioning based on Global Navigation Satellite System (GNSS) technique requires high accuracy ionospheric total electron content (TEC) correction models to account for the ionospheric path delay errors. We present an adjusted Spherical Harmonics Adding KrigING method (SHAKING) approach for regional ionospheric vertical TEC (VTEC) modeling in real time. In the proposed SHAKING method, the VTEC information over the sparse observation data area is extrapolated by the Adjusted Spherical Harmonic (ASH) function, and the boundary distortion in regional VTEC modeling is corrected by the stochastic VTEC estimated using Kriging interpolation. Using real-time GPS, GLONASS and BDS-2/3 data streams of the Crust Movement Observation Network of China (CMONOC), the SHAKING-based regional ionospheric VTEC maps are re-constructed over China and its boundary regions. Compared to GNSS VTECs derived from the independent stations, the quality of SHAKING solution improves by 13–31% and 6–33% with respect to the ASH-only solution during high and low geomagnetic periods, respectively. Compared to the inverse distance weighting (IDW) generated result, significant quality improved of SHAKING-based VTEC maps is also observed, especially over the edge areas with an improvement of 60–80%. Overall, the proposed SHAKING method exhibits notable advantage over the existing regional VTEC modeling techniques, which can be used for regional TEC modeling and associated high-precision positioning applications.