Study On The Application Of Oblique-axis Lambert Projection In The Plane Coordinate System Of High-speed Rail

In the process of high-speed railway construction,it is necessary to project the actual engineering.Gaussian projection is one of the most commonly used projection methods.The characteristics of the Gaussian projection make it possible to effectively solve the problem of limiting the maximum length deformation of the projection.However,in the actual projection application,the Gaussian projection has a small east-west control range when satisfying the high-speed railway accuracy requirement.When the project scope is large,multiple projection zones need to be established,which maks the coordinate transformation between the various projection zones complicated and harm the calculation.Moreover,the large deformation of the projection belt edge is not conducive to maintaining the actual engineering accuracy,so we need to establish more independent coordinate systems based on the actual project,which makes the actual engineering calculation more cumbersome.Therefore,when studying the actual construction of a high-speed railway in an oblique direction,according to the characteristics of the Gaussian projection,the control range of the projection tape is optimized or the length deformation is increased,so that the projection coverage of the Gaussian projection meeting the engineering measurement accuracy is increased,or we could replace the Gaussian projection with a new projection analysis method.This article will study the projection method of the oblique-axis Lambert projection and analyze its application in the high-speed railway engineering project in the oblique direction.1.By introducing various basic theories related to oblique-axis Lambertian projections,it provides a theoretical foundation for the application analysis of oblique-axis Lambertian projections.At the same time,this paper mainly studies the application of inclined-axis Lambert projection in the high-speed rail plane-coordinate system,and then briefly summarizes and discusses the measurement method and precision requirements of high-speed railway control network.2.This paper analyzes how to establish a plane coordinate system for oblique-axis Lambert projections.According to the establishment of the plane coordinate system of the positive axis Lambertian projection,the oblique axis Lambert projection is introduced to establish the plane coordinate system.In the conversion between the positive axis Lambertian projection and the oblique axis Lambertian projection,the spherical coordinates play a role of the conversion medium.After comparing and analyzing the length deformations of the oblique-axis Lambertian projection and the Gaussian projection,the control range and the advantages and disadvantages of the deformation are determined.Thus,the commonly used Gaussian projection and the inclined-axis Lambbert projection studied in this paper have a clear comparison which makes the scope of control in the study suitable for engineering studies avoiding over-limitation.At the same time,the least squares method can be used to determine the position of the best projection centerline of the oblique-axis Lambertian projection.This is a very important part of the study of oblique-axis Lambertian projections and the establishment of oblique-axis Lambert projection coordinate systems.3.By comparing the oblique-axis Lambertian projection with Gaussian projection in the low altitude region and comparing the oblique-axis Lambertian projection with the Gaussian projection in the higher altitude region,this paper analysis the advantages and disadvantages.Finally,according to the research and comparison of data,it is concluded that using the oblique-axis Lambertian projection has obvious advantages compared with the Gaussian projection in the construction of the high-speed railway engineering coordinate system in the oblique direction.In this paper,through the comparison and analysis of inclined-axis Lambertian projection and Gaussian projection in high-speed railway engineering,it is concluded that the oblique-axis Lambertian projection is more suitable for the data processing and analysis research of high-speed railway engineering construction in the tilt direction.The method has great advantages in zoning,and reduces the complicated for mula conversion between bands,which has certain reference value for the research,analysis and application of this type of engineering project.