CORS system establishes a number of continuous permanent reference stations in a certain area, and connects them through the network to form a networked GNSS integrated service system. Each fixed reference station does not directly send any correction information to the mobile users, but sends all the original data to the control center through the data communication line.

At the same time, the mobile user sends a rough coordinate to the control center through the short message function of GSM before work. After the control center receives this position information, the computer automatically selects the best set of fixed reference stations according to the user's position. According to the information sent by these stations, the errors caused by GPS orbit error, ionosphere, troposphere and atmospheric refraction are corrected as a whole, and high-precision differential signals are sent to mobile stations. This differential signal is equivalent to generating a virtual reference base station next to the mobile station, thus solving the problem of RTK working distance limitation and ensuring the accuracy of users.