A Correction Model of Troposphere Delay for GNSS Signal in the Dust and Haze Weather

Tropospheric delay is a factor that affects GNSS positioning accuracy, and the instability of the tropospheric refractive index is the cause of the deviation of tropospheric delay compensation. In the case of taking into account the atmospheric water vapor content and the atmospheric temperature of the station, this paper simplifies the establishment of a parametric refractive index correction model to replace the refractive index model that depends on meteorological factors. The parameters of the correction model are determined by the tropospheric layering method. The results show that under the same weather conditions, the accuracy in northern Shaanxi is higher than that in Guanzhong, and the correction value of refractive index is not ideal when it is far from the ground. Based on the model to estimate the ZTD, the results are compared with the results obtained by three IGS stations (LHAZ, BJFS, SHAO), which confirms that the accuracy of the ZTD estimation is generally improved by the model.