Evaluation of ionospheric height assumption for single station GPS-TEC derivation

To investigate the effects of ionospheric single thin layer height on GPS based total electron content (TEC) derivation by a single station, the GPS dual frequency pseudoranges and carrier phases received in Beijing at solar minimum and maximum are used for derivation at different heights through grid method, Kalman filtering method and polynomial method respectively. Detailed analyses proceed to be conducted on derived vertical TEC (VTEC) and estimated instrumental biases as well as residual errors of slant TEC (STEC) and errors of satellite biases, during which derived VTEC is compared with VTEC offered by CODE and IRI2012. VTEC at receiver zenith derived through three methods tends to increase with the height, whereas that through grid method at relatively large height may be unsolvable. Biases estimated via Kalman filtering method and polynomial method are less affected by the height. Those via grid method at height below 400 km are similar to those via other two methods, but the errors rise sharply above that value. Under the research condition the optimum height for Kalman filtering method as well as polynomial method at solar minimum is 380 km, and 310 km at solar maximum, while for grid method the optimum height ranges from 280 km to 350 km.