Search

The GNSS receiver performs real-time satellite differential positioning and broadcasts RTK differential data as an RTK base station when GNSS mobile base station technology is applied in port and waterway engineering, by conducting a series of tests to evaluate the RTK positioning performance of the rover station. A test scheme about real-time dynamic positioning was developed by selecting a typical port and waterway engineering area located at the Yangtze River estuary. Referring to the synchronous PPK positioning results, the accuracy and influencing factors of RTK rover station and the stability of zero baseline in real-time dynamic positioning mode were analyzed. The experimental shows that the N and E directions of the RTK rover station can converge within 3 min, and the deviation RMS is less than 1.0 cm within 20 min after convergence; The H direction can converge within 4 min, and the deviation RMS is less than 3.0 cm within 20 min after convergence. When the relative distance between the mobile base station and the RTK rover station is too large or the relative height difference is suddenly reduced, the RTK rover station is prone to poor positioning. The difference in Nor E directions of the zero baseline positioning of two rover stations kept at millimeter level and the difference in H direction is less than 依1.5 cm, indicating high stability in positioning and orientation. [ABSTRACT FROM AUTHOR]

This paper takes the Ocean α SL40 autonomous unmanned survey boat used in the main reclamation works of Hong Kong International Airport three runway system project as an example to introduce the basic principles and workflow of the unmanned survey boat by using Hong Kong satellite positioning reference station network to conduct network RTK for bathymetric survey without the tide gauge. It shows that the unmanned survey boat system based on network RTK has a higher measurement accuracy and good adaptability in a special marine environment, which could provide more choices for the bathymetric survey of reclamation projects. [ABSTRACT FROM AUTHOR]