A satellite-based method for modeling ionospheric slant TEC from GNSS observations: algorithm and validation

Abstract Total Electron Content (TEC) modeling is critical for Global Navigation Satellite System (GNSS) users to mitigate ionospheric delay errors. The mapping function usually used Vertical TEC correction models slant and vertical conversion. But the cannot characterize variation in different azimuths between user satellites. error resulting from tends be bigger middle low latitudes. Therefore, a new algorithm Slant (STEC) with Satellite-based Ionospheric Model (SIM) proposed this contribution. Validation tests are carried out GNSS observation data Crustal Movement Observation Network of China during solar activities seasons. performance SIM compared that several commonly-used Map (GIM) Regional (RIM) products. results show STEC bias STD within 1.0 TECU about 2.0 TECU, respectively, can correct over 90% RMS errors, outperforming GIM RIM Consequently, option high-accuracy regional local networks.