Real‐Time Monitoring of Ionosphere VTEC Using Multi‐GNSS Carrier‐Phase Observations and B‐Splines

Monitoring the Vertical Total Electron Content (VTEC) of ionosphere is important for applications ranging from navigation to detection space weather events. Therefore, emerging efforts have been made by several analysis centers estimate VTEC using different approaches in real-time. Global Navigation Satellite Systems (GNSS) a crucial technology modeling due its worldwide distributed receivers, high temporal resolution, and low latency data dissemination capability. The selection convenient approach extract information GNSS representation an appropriate mathematical model are essential factors providing fast accurate products. Contrarily widespread phase-leveling method, which uses noisy erroneous code measurements, concept this paper utilizes pure carrier-phase measurements. Measurements acquired through International Service (IGS) real-time service Radio Technical Commission Maritime Services format GPS, GLONASS, GALILEO. measurement biases, including ambiguity simultaneously estimated along with parameters. In our approach, represented B-spline expansions embedded into Kalman filter. Due their localizing feature, B-splines form highly sparse structure filter model. Thus, matrix operations large-scale problems can be performed operations, as done study. differential slant total electron content (dSTEC) comparison Jason-3 altimetry were validation within selected periods 2019. dSTEC shows that quality generated maps slightly outperforms those provided other IGS centers.