The role of network RTK

The working principle of RTK determines that RTK measurement needs at least two instruments, a reference station and ≥ 1 mobile station. The reference station observes the satellite and sends the data to the mobile station in real time through the data link. The mobile station combines the data of the reference station to calculate and get the centimeter-level positioning coordinates. In the traditional RTK mode, data is transmitted between the reference station and the rover station by radio, and the signals in different time periods are relatively stable. However, every time the operation is relocated or the base station moves unexpectedly, the base station needs to be rebuilt, and the error accumulates with the distance of the mobile station, so the operation distance is limited. The appearance of network RTK has solved the problems of limited distance and repeated erection of reference stations.

In network RTK, there are many reference stations, so users don't need to build their own reference stations, and the distance between users and reference stations can be extended to hundreds of kilometers.

Its basic principle is to lay out the reference station network sparsely and evenly in a large area, and then learn from the basic principles and methods of wide-area differential GPS and multi-reference station local differential GPS to eliminate or weaken the influence of various system errors as much as possible and obtain high-precision positioning results.

Network RTK consists of reference station network, data processing center and data communication line. The reference station network collects observation data in real time and transmits the data to the data processing center through the data communication chain. The data center judges the area where the mobile station is located according to the approximate coordinates of the mobile station, and then broadcasts the system error information to the mobile station, and the mobile station corrects the observation data according to the received error information, thus obtaining accurate observation data.

In the past, the traditional RTK work required at least two receivers, so it was very troublesome to move around in the field work. The network RTK only needs a receiver with GPRS module, and the centimeter-level positioning coordinates can be obtained by logging into the local cors system through the connection software, which greatly reduces the labor intensity of field work.