Abstract: Based on the study of the existing real-time ionospheric estimation methods，the calculationformula for TEC using a combination of pseudo-range and carrier phase observations is proposed inthis paper. Hardware delay deviation is also considered. Using simulated real-time observations fromeight stations in Hubei province，estimated TEC results for the UPS and BeiDou systems were obtamed for each station and compared with the UIM model. Numerical results showed that:the estimated TEC results from both systems are consistent with UIM in its magnitude and trend. In addition，the RMS of UPS was maintained within 4 TECU while the BeiDou was 5 TECU. The results show that the method can achieve real-time TEC for the BeiDou satellite navigation system and canmonitor the ionospheric activity independently.