The current situation and development of the commonly-used geocentric coordinate system in China

In this paper, the current status of CGCS2000, BeiDou coordinate system (BDCS) and WGS-84 coordinate system in common use in China is introduced, the connection and difference between them are analyzed, the existing problems and limitations are pointed out, and some suggestions for the further development of CGCS2000 and BDCS in China are put forward by referring to foreign experience. CGCS2000 reference frame has been established for more than 20 years. It is not current and is more suitable for 2D coordinate application scenarios requiring unity and stability. Therefore, it should be maintained continuously and updated regularly. There are tens of thousands of continuously operating refererce station (CORS) in China, and it is necessary and conditional to establish a real-time reference frame in China for higher precision 3D coordinate application scenarios. For a long time, people used to refer to the Global Navigation Satelite system (GNSS) coordinates as WGS-84, which became synonymous with the geocentric coordinate system. In production practice, it is not important which coordinate system a geocentric coordinate belongs to, but the three elements of a geocentric coordinate must be focused on, such as precision, calendar element and frame. There is no essential difference between BDCS and WGS-84. Based on the practice of NGA, the concept of BDCS ground-based and space-based reference frame is expanded to make BDCS global, current and accurate at the same time. The role of the BDCS reference framework after concept extension is equivalent to “WGS84+IGS”. In digital Earth, 3S integration, smart city and other applications, CGCS2000 and BDCS dual benchmark services can be adopted. Based on THE CGCS2000 base map, the expanded BDCS benchmark can be used in high-precision applications, which can take into account the standards and the current situation, and meet the needs of globalization and precision.