Method for establishing engineering area level ellipsoids

Abstract

The invention discloses a method for establishing engineering area level ellipsoids. The method comprises following steps: an engineering area level ellipsoid function composed of undetermined parameters is established on the basis of a standard ellipsoid function; by means of abnormal data of control point elevation, on the basis of a testing zone average elevation plane, the control point elevation is converted to the testing zone average geoid corresponding to the testing zone average elevation plane to obtain a testing zone ellipsoid surface point spatial rectangular coordinate under a source ellipsoid; translation parameters and long and short axis parameters are obtained under the coordinate; a new engineering level ellipsoid E1 is established through translating and adjusting the long axis and the short axis, and the spatial coordinate under a target ellipsoid is obtained; geodetic coordinate transformation, where the ellipsoid long axis and short axis are changeable, is performed on the converted coordinate under the engineering level ellipsoid E1 and further the coordinate is converted to an engineering plane coordinate for further accurate reduction. The level ellipsoid plane established by the method can be well matched with the geoid corresponding to the engineering testing zone average elevation plane, which facilitate data accurate deduction.

Description

technical field [0001] The invention belongs to the field of geographic surveying and mapping science and technology, and in particular relates to a method for establishing a leveling ellipsoid in an engineering area. Background technique [0002] The ideal state of an engineering ellipsoid is that its reference ellipsoid coincides with the geoid of the survey area, that is, the ellipsoid is an equipotential surface in the normal gravity field. The engineering reference ellipsoid is the datum plane for engineering surveying and calculation, as well as the reference plane for studying the shape of the earth and map projection, so the engineering ellipsoid must satisfy the basic constants (a,b,GM,w) of the geodetic reference system, while the earth's The gravity equipotential surface is an irregular surface, which does not satisfy the basic constants of the geodetic reference system. Therefore, there is no reference ellipsoid that satisfies both the basic constants of the geod...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a method for establishing a leveling ellipsoid in an engineering area, and constructs the parameters of the ellipsoid that are optimally close to the survey area under the existing data, which solves the problem that the existing engineering ellipsoid cannot be aligned with the geoid of the entire engineering area better fit problem

Images