Real-time Estimation of Tropospheric Slant Delay in Two-way Troposphere Time Transfer

Tropospheric slant delay is a main error source in two way time transfer via tropospheric scatter communication. A method for real-time estimation of tropospheric slant in two way time transfer via tropospheric scatter communication is proposed. The meteorological data of the station are calculated by the GPT2w model to overcome the reliance on the real-time meteorological data in the estimation of tropospheric delay. In order to solve the problem of the fixed height of the top troposphere layer, the real height of the top troposphere layer is calculated by geometric method to solve the practical application. Three stations in Japan are selected and compared with each other. After verifying the accuracy of the Hopfield model, the tropospheric delay of the three groups at different angles and different time is calculated. The results show that the tropospheric slant delay in two-way troposphere time transfer increases with the increase of the distance, and decreases with the increase of the angle, and the variation characteristics of the four seasons are obvious. The tropospheric delay of the three stations is between 10 similar to 35 m, and the time delay after subtracting 90% is 3.5 similar to 11.8 ns.