The Application of Lambert Projection in Overseas High-speed Railway Projects
In response to the current lack of universal Lambert projection coordinate transformation and length deformation calculation software,this article summarized the Lambert projection formula and developed a Lambert projection coordinate calculation software.Taking a high-speed railway project in Morocco as an example,this paper compared the coordinate transformation results of the software with those of EPSG and a certain Gaussian coordinate transformation software.At the same time,the length deformation of the Lambert projection for this project was calculated,and the law of length deformation was analyzed.The calculation results indicate that,the software can achieve the calculation of Lambert projection coordinates with different parameters.The calculation accuracy of the software in this paper can be accurate to four decimal places,meeting the needs of Lambert projection zone change calculation.The calculation results of length deformation show that,when there is no undulation on the ground,both the Lambert tangent projection and the Lambert secant projection can control the length deformation within±10 mm/km in the area with a latitude difference of 0.7°,which means that in the absence of undulations on the ground,the length deformation control ability of the two projections is the same.The establishment of an engineering independent coordinate system using the Lambert tangent projection with simple deformation patterns is suggested for priority use.
high-speed railwayLambert projectionprojection zone changelength deformation
NETL
NSTL
万方数据
