Analysis of Network RTK Survey Accuracy Based on Railway Banded BeiDou CORS in High-altitude and Dangerous Mountainous Areas.

In order to study and expand the application of BeiDou Navigation System in railway engineering survey, the technical advantages of BDS system are used to solve the problem of railway surveying and positioning in mountain areas. Based on a railway in mountain areas, this paper has established a belt-shaped BeiDou continuous operation reference station system (hereinafter referred to as "BeiDou CORS System") and a high-precision location service cloud platform. The domestic multisatellite and multi-frequency survey receiver is used to collect the data of control points. The survey accuracy of RTK observation data of BDS, GPS and GNSS hybrid ephemeris network based on BeiDou CORS System and RTK observation data in the form of traditional base stations are compared respectively. The results show that: (1) The positioning function of network RTK based on railway banded BeiDou high-precision location service cloud platform is stable and reliable; (2) The network RTK measurement method based on the Beidou CORS system only needs to perform elevation surface fitting, and the accuracy of the results collected in 3s can meet the accuracy requirements of the network RTK center line survey, section survey, construction stakeout, and image control survey in the railway survey code. The same type of equipment and the same precision observation method should be used as much as possible to ensure the repeated survey accuracy, and the survey accuracy can also be improved by increasing the observation time and using the existing elevation control points for elevation correction in local areas; (3) The internal coincidence accuracy tolerance of plane and elevation of network RTK survey based on BeiDou CORS System can be set to 1.7 cm and 2 cm, and the outer coincidence accuracy can be set to 2.2 cm and 5 cm. [ABSTRACT FROM AUTHOR]