Design Of Surveying And Mapping System Based On GNSS And Its Application In High-speed Railway Construction

For the design,construction,operation of the project,the engineering mapping is of great significance.Most traditional mapping work uses offline operations,the internal managers and engineers use paper forms for task distribution and results recording,this approach has directly led to the situation of difficult management and low efficiency.In addition,the requirements of on-site operation are complicated,the engineers are required to make accurate judgment according to the scene conditions with the help of the self-contained function of the measurement equipment,resulting in that certain task types have very high requirements on engineers' professional qualities.At the same time,based on different application scenarios,the data may need to be converted into multiple coordinate systems.The traditional artificially dependent method not only fail to guarantee efficiency but also introduce errors easily.Based on the above reasons,this thesis designs a set of online engineering surveying and mapping system based on GNSS measurement technology,and takes the construction site of the high-speed railway as a test application scene.The main achievements are as follows:(1)Online management.After fully investigating the working process of the construction site,this thesis designs a set of online mapping management process based on B/S architecture,which divides the responsibilities of the internal manager and the outer engineer so that they can work together to complete the task online.(2)Visual construction.The system changes the traditional equipment-dependent operating mode,transforms the mapping work to the browser side,and provides a visual construction interface to carry out mapping operation in a more intuitive and more convenient way.(3)Digital mapping results.To get rid of the offline recording method,the system stores all the data in the cloud database,saves the mapping results through the service interface,then the manager can manage the platform and generate a report of the result.(4)Automatic coordinate conversion.The built-in algorithm conversion module of the system solves the rover space coordinates,uses them as the source data and automatically converts into the earth coordinates,the plane coordinates and the construction coordinates to avoid manual intervention,enhance the convenience while ensuring data reliability.The system is easy to install,provides multi-terminal access,and has been applied to the on-site construction test of the eighth section of the new Jing-Zhang railway project.Judged that the system can achieve the accuracy of 1cm in the horizontal direction and 2cm in the elevation direction,fully meet the engineering requirements of the construction mapping work.