Matrixes of nonlinear distortions

Usually, the coordinates of ground control points have nonlinear distortions, caused by different factors (errors of measurement, displacement of points images on photographs, errors of scanning). To estimate these distortions it is possible on residual divergences on ground control points at a choice of affine type of transformation offset, rotate, scale.

To eliminate nonlinear distortions it is possible having applied one of nonlinear methods of transformation. After calculating the parameters of transformation it is possible to build the matrix of nonlinear distortion for X and Y, having clicked the button «Build matrix». Matrixes of nonlinear distortions are necessary only for the analysis of a surface of nonlinear distortions and are not used at transformation of a vector map.

Matrixes are created in the source system of coordinates and after construction are added to the input map. Into matrixes there is written the difference between the coordinates calculated by formulas of nonlinear transformation and transformation of offset, rotate, scale. Comparing the matrix distortion, you can choose transformation, optimal for solving a specific task.

Matrixes are created with the predetermined names:

- matrix distortion on X - Map name_X.mtw;

- matrix distortion on Y - Map name_Y.mtw;

- matrix of planned distortion - Map name_XY.mtw;

At creation of already existing matrix the old matrix is deleted without saving.