Abstract. We recently proposed a method to establish an optimal ionospheric shell
height model based on the international GNSS service (IGS) station data and
the differential code bias (DCB) provided by the Center for Orbit Determination
in Europe (CODE) during the time from 2003 to 2013. This method is very
promising for DCB and accurate total electron content (TEC) estimation by
comparing to the traditional fixed shell height method. However, this method
is basically feasible only for IGS stations. In this study, we investigate
how to apply the optimal ionospheric shell height derived from IGS station
to non-IGS stations or isolated GNSS receivers. The intuitive and practical
method to estimate TEC of non-IGS stations is based on optimal ionospheric
shell height derived from nearby IGS stations. To validate this method, we
selected two dense networks of IGS stations located in regions in the US and
Europe. Two optimal ionospheric shell height models are established by two
reference stations, namely GOLD and PTBB, which are located at the
approximate center of two selected regions. The predicted daily optimal
ionospheric shell heights by the two models are applied to other IGS
stations around these two reference stations. Daily DCBs are calculated
according to these two optimal shell heights and compared to respective DCBs
released by CODE. The validation results of this method are as follows. (1) Optimal ionospheric shell height calculated by IGS stations can be applied
to its nearby non-IGS stations or isolated GNSS receivers for accurate TEC
estimation. (2) As the distance away from the reference IGS station becomes
larger, the DCB estimation error becomes larger. The relation between the
DCB estimation error and the distance is generally linear.
Validation and application of optimal ionospheric shell height model for single-site estimation of total electron content