Differential areas for differ-ential stations (DADS): A new method of establishing grid ionospheric model

Differential Area for Differential Stations (DADS), a new method of establishing grid ionospheric model, is presented. The preliminary results show that it is possible to establish a real time large range high precision grid ionospheric model (GIM) using the DADS and the GPS data of the Chinese crust movement observation network (CCMON).