CORS Double-Difference Ionospheric Delay Interpolation Model  Accuracy Analysis Over Long Distances

In order to verify whether the traditional interpolating model can meet the requirement of double-difference ionospheric delay accuracy of the continuously operating reference station CORS system at a long distance. By constructing an ionospheric double-difference observation equation, linear interpolation model (LIM) and distance-dependent linear interpolation model (DIM) are taken as the research object, and virtual reference station technology (VRS) is represented as the representative monitoring station. The differential ionospheric delay is compared with the double-difference ionospheric delay of the monitoring station obtained by LIM and DIM interpolation algorithm.  The two models are analyzed under the longdistance CORS network. The double difference ionosphere delay interpolation effect. The experimental results show that the interpolation accuracy of the LIM model is higher than that of the DIM model under the condition of the remote CORS network monitoring station.