Three-dimensional coordinate conversion method

Abstract

The invention relates to a three-dimensional coordinate conversion method, which determines a local coordinate system through selection of a reference point and solves seven parameters of coordinate conversion through an optimized nonlinear least square method so as to solve the problem of conversion from a measurement coordinate system to a local plane coordinate system. The method comprises thefollowing steps: firstly, selecting three reference points to determine the local plane coordinate system, then calculating coordinates of the reference points in the local coordinate system by usingspace geometry, and then solving seven parameters of coordinate conversion by using an optimized nonlinear least square method. The optimization mode is that iterative correction is carried out on aniterative initial value of the nonlinear least square method, and the nonlinear least square method is repeatedly carried out for solving until seven parameter values meeting the precision requirementare found. According to the method, extra local coordinate system information is not needed, meanwhile, the problem that a traditional seven-parameter calculation process is not converged is solved,finally, a single seven-parameter value meeting the precision requirement can be obtained, and therefore efficient, stable and accurate coordinate conversion is achieved.

Description

technical field [0001] The invention relates to the field of surveying and mapping, in particular to a three-dimensional coordinate transformation method. Background technique [0002] In the field of surveying and mapping, since the measurement coordinate system is inconsistent with the local plane coordinate system, in the measurement coordinate system, the measurement result obtained by horizontal movement is usually an inclined plane instead of a horizontal plane. In order to be intuitive and convenient for subsequent processing, the measurement coordinate system is generally converted to the local plane coordinate system. [0003] There are many methods of coordinate conversion, and the usual method is to use software to convert one by one, and the coordinates of the control points need to be input one by one during the conversion process, which is cumbersome to operate. Another commonly used transformation method is to solve the seven parameters of coordinate transfor...

AI Technical Summary

Problems solved by technology

[0005] This method avoids the non-convergence and insufficient accuracy of the results that may be caused by the iterative initial value selection in the single nonlinear least squares method, and can finally solve the conversion problem from the measurement coordinate system to the local plane coordinate system

This method only needs the coordinates of one point in the local coordinate system to obtain the coordinates in another coordinate system through spatial geometric operations, without additional local coordinate system information, and solves the problem that the traditional seven-parameter calculation process does not converge. Finally, a single seven-parameter value that meets the accuracy requirements can be obtained, thereby achieving efficient, stable and accurate coordinate conversion

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