The four permanent benchmarks are built as the altitude controlnetwork in the place because of the requirement for the CSPC Nanhai petrochemical project's building.
中海壳牌南海石化项目因工程建设的需要，在厂区范围内建立了四个永久性水准点作为场地高程控制网。
2
The accuracy and efficiency of the application of GPS in forest districts were improved effectively after building the GPS controlnetwork.
建立林区GPS控制网后，GPS在林区应用的精度和效率大大提高。
3
The PLC performance of the communication nodes is tested and analyzed. The results show the communication system of the controlnetwork of intelligent building is feasible.