Abstract:Using GNSS and radiosonde data, a new inversion method is presented for troposphere refractivity index. A layered profile inversion model of parameters of refraction index above stations is constructed by combining radiosonde data and the high accuracy ZTD(zenith troposphere delay), which we estimate directly by GNSS observations of stations. Based on measured data from BJFS(Beijing station), WUHN(Wuhan station), WIND(Windhoek station) and DARW(Darwin station), this paper has accomplished corresponding calculations and validation. Eventually, the result shows that the new inversion model method and inversion model based on radiosonde data has the same accuracy, and their accuracy is even better compared with the inversion model of Hopfield. Furthermore, the new method is easy to calculate, and observations from radiosonde are greatly reduced when the new model is established.