Method of Controlling Gaussian Projection Deformation Based on Normal Section Meridian Ellipsoid

Abstract

The invention discloses a method for controlling Gaussian projection deformation based on a normal section meridian ellipsoid. The basic technical thought is that: a new ellipsoid is constructed, so that the direction of a central meridian is basically consistent with a line extension direction, and projection deformation along a line central line extension direction is close to zero. The method comprises the following steps of: (1) constructing a normal section meridian ellipsoid E4; (2) converting the space rectangular coordinate of an ellipsoid E0 into the space rectangular coordinate of the ellipsoid E4; (3) converting the space rectangular coordinate of the ellipsoid E4 into a geodetic coordinate; (4) converting the geodetic coordinate of the ellipsoid E4 into a Gaussian plane coordinate; (5) calculating the Gaussian projection deformation value of the ellipsoid E4; and (6) comparing the Gaussian projection deformation value of the ellipsoid E4 with a projection deformation limitvalue, and verifying. By the method, the Gaussian length projection deformation of a long and large line can be effectively controlled, the number of projection zones is greatly reduced, and the method is particularly suitable for east, west, non-south and non-north long and large line engineering.

Description

technical field [0001] The invention belongs to the field of surveying and mapping science and technology, and specifically relates to a method for controlling Gaussian projection deformation based on a normal section meridian ellipsoid to establish an independent coordinate system for projects in long-term line projects (high-speed railways, passenger dedicated lines, expressways, oil pipelines, and power lines) . Background technique [0002] The ellipsoid is a convex surface that cannot be flattened. If the elements (distance, direction, angle, and graphics) on this surface are projected onto the plane, they must be the same as the original corresponding elements (distance, direction, angle, and graphics). This difference is called projection distortion. Projection deformation includes length deformation, direction deformation, angle deformation and area deformation. In map projections, projection distortion is unavoidable, but it can be mastered and controlled as neede...

AI Technical Summary

Problems solved by technology

Using these methods, the difficulty of long-term east-west and non-north-south lines lies in the frequent change of belts, and the uniqueness of coordinates cannot be guaranteed

The transformation effect of the ellipsoid expansion method, ellipsoid translation method, and ellipsoid deformation method is to expand, translate or translate and expand at the same time, so that the ellipsoid surface is as close as possible to the projection surface of the survey area, that is, the average elevation surface, which solves the problem of elevation normalization correction, Does not account for Gaussian projection distortions for ellipsoid-oriented planar mapping, nor does it expand the width of the projection bands

[0005] For long-term line projects (high-speed railways, passenger dedicated lines, expressways, oil pipelines, power lines), the measurement and control range appears as a straight linear range, which can be delineated by a rectangle with a small width and a long length, and the east-west span is relatively large Within the scope of the project, it is difficult to overcome the length projection deformation caused by the large east-west span by using the above four methods of Gaussian projection, and it cannot reduce the number of projection zoning

Images