Method for improving time service precision of eLoran system by using ASF grid and differential station

The invention provides a method for improving the time service precision of an eLoran system by using an ASF grid and a differential station, and the method comprises the steps: enabling the differential station to carry out the real-time time difference measurement, calculating a differential correction model, and transmitting the differential correction model to surrounding users; establishing an ASF grid database by utilizing the dynamic measurement data and an inverse bilinear interpolation algorithm; enabling the user to calculate own one-time delay, and calculate a difference correction number according to the difference information to obtain a time component of the ASF; secondly, searching for a grid where the ASF is located, and calculating spatial components of the ASF according to the position information and ASF values of four vertexes of the grid; and finally, correcting the signal propagation time delay by using the time component and the space component to obtain more accurate signal propagation