Calculation method of oblique axis gaussian projection based on equal length of geodesic

Abstract

The invention relates to an oblique axis Gaussian projection calculation method based on the equal length of a geodetic line, wherein a certain geodetic line is taken as a central meridian, projectedas a straight line, the length is kept constant, and the oblique axis Gaussian projection is realized. At the same time, it is agreed that the oblique Gaussian projection satisfies three basic conditions: the oblique Gaussian projection is a conformal projection, that is, an isometric projection; The geodesic line is a straight line after projection, and it is the symmetry axis of projection. Thelength remains unchanged after the geodesic line is projected. A line of earth is envisage as a central meridian, project as a straight line, With the help of geodetic-like latitude, normalized-like latitude, isometric-like latitude and isometric-like latitude, the hypothesis of geodetic mapping ellipse is put forward and proved. On the basis of the hypothesis, the expression of geodetic arc length and the complex and real formulas of oblique axis Gaussian projection based on a geodetic equilength are deduced. The real oblique axis Gaussian projection is realized and the deformation of lengthprojection is solved.

Description

technical field [0001] The invention belongs to the technical field of establishment of a length projection deformed coordinate system and coordinate conversion, and in particular relates to an oblique-axis Gaussian projection calculation method based on geodetic equal lengths. Background technique [0002] In recent years, the construction of high-speed railway passenger dedicated lines has been carried out on a large scale. "Specifications for High-Speed ​​Railway Engineering Survey" (TB10601-2009) stipulates: "The plane coordinate system of high-speed railway engineering measurement should adopt the independent coordinate system of the project, and the projected length deformation value of the coordinate system on the corresponding track surface design elevation plane should not be greater than 10mm / km". Among them, the project independent coordinate system in clause 2.1.1: the planar rectangular coordinate system established by using any central meridian and elevation ...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a calculation method based on the oblique-axis Gaussian projection of the same length of the geodetic line, which meets the restrictions on the projection deformation of the railway industry standard, and solves the problem of long and long lines. The length projection deformation of the engineering coordinate system and the problem of carrying out the design of the independent coordinate system of the engineering

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