Real-Time Offshore BDS-3 Single-Station Ionospheric TEC Retrieval Method and Experimental Validation

Real-time ionospheric total electron content (TEC) retrieval is crucial for ionospheric electron density inversion and ionospheric scintillation detection. GNSS is currently the most effective technology for TEC retrieval. However, there is lack of research on the real-time single-station TEC retrieval methods for marine observation platforms. To address this issue, a real-time offshore BDS-3 single-station ionospheric TEC retrieval method is proposed in this paper. To verify the accuracy of this method, an experimental system is implemented at offshore station in Qingdao for 12 days using undifferenced uncombined precise point positioning (UUPPP) and carrier phase smoothing pseudorange (CPSP) models in ionospheric TEC retrieval. By comparing with Global Ionospheric Map (GIM) products, the RMS of TEC bias of the UUPPP and CPSP models are 14.2 and 19.5 TECU respectively. The results prove that compared with the CPSP model, the UUPPP model is more resistant and stable, which indicates that the UUPPP model is more suitable for offshore observation platforms such as ships and buoys where GNSS signals are more susceptible to radio frequency (RF) interference.