In this section you can transform the coordinates of the points from one system to another using 3D transformation.

You can also perform this transformation for points with coordinates (X, Y, Z) that aren’t in the two predefined coordinate systems for the A and B system. In this case, the transformation of coordinates from (X, Y, Z) to (φ, λ, h) or to (N, E, H) from inside the tables isn’t available any more.

Transformation method

The supported transformation methods are:
• conformal 3D transformation the Bursa-Wolf method (7 parameters);
• conformal 3D transformation the Molodenski-Badekas method (10 parameters);
• conformal 3D Helmert transformation (7 parameters);
• affine 3D transformation (8 parameters);
• affine 3D transformation (9 parameters);
• affine 3D transformation with rotation origin (12 parameters);
• time-dependent 3D transformation, Bursa-Wolf method (15 parameters);
• time-dependent 3D transformation, conformal Helmert (15 parameters).

For information on the manner of selecting the transformation method read the page with Recommendations.

Parameters

Parameters can be typed, loaded from a file or from the EPSG database or copied from another parameters box. The description of the buttons and of the contextual menu of the parameters group box can be found at The contextual menu of the parameters group box.

The file with parameters must contain a number of lines equal with the number of parameters + 1 with the following information:
1. text with the description of the transformation parameters;
2. the Xo coordinate rotation origin (line that appears only for the transformation with 10 and 12 parameters);
3. the Yo coordinate rotation origin (line that appears only for the transformation with 10 and 12 parameters);
4. the Zo coordinate rotation origin (line that appears only for the transformation with 10 and 12 parameters);
5. the translation on X (Tx);
6. the translation on Y (Ty);
7. the translation on Z (Tz);
8. the rotation around the X axis (Rx) in sexagesimal seconds;
9. the rotation around the Y axis (Ry) in sexagesimal seconds;
10. the rotation around the Z axis (Rz) in sexagesimal seconds;
11. the scale factor on X in ppm;
12. the scale factor on Y in ppm (line that appears only for the transformation with 8, 9 or 12 parameters);
13. the scale factor on Z in ppm (line that appears only for the transformation with 9 or 12 parameters);
14. rate of change of X-axis translation (line that appears only for the transformation 15 parameters);
15. rate of change of Y-axis translation (line that appears only for the transformation 15 parameters);
16. rate of change of Z-axis translation (line that appears only for the transformation 15 parameters);
17. rate of change of X-axis rotation (line that appears only for the transformation 15 parameters);
18. rate of change of Y-axis rotation (line that appears only for the transformation 15 parameters);
19. rate of change of Z-axis rotation (line that appears only for the transformation 15 parameters);
20. rate of change of scale difference (line that appears only for the transformation 15 parameters);
21. epoch reference (line that appears only for the transformation 15 parameters).

In the case of the transformation with the method Bursa-Wolf with 7 or 15 parameters or Molodenski-Badekas with 10 parameters the rotations are accepted only for values between -10” and +10”. This limitation is given by the used mathematical method; you can find the description at Used Formulas.

The reversal of parameters can be made ​​only for the methods "conformal 3D transformation the Bursa-Wolf method (7 parameters)", "conformal 3D Helmert transformation (7 parameters)" and "time-dependent 3D transformation, Bursa-Wolf method (15 parameters)". For these three methods as well for the method "time-dependent 3D transformation, conformal Helmert (15 parameters)" you can apply the reverse transformation using forward transformation parameters.

In the Parameters calculation section from the main program you can calculate and save these parameters to a file.

Coordinates tables

In the two tables the coordinates can be typed, loaded from a file or copied from another table. The coordinates from tables can be saved to file or can be exported to Microsoft Word or Microsoft Excel. The description of the buttons and of the contextual menu of the tables can be found at The commands of the coordinate tables.

The loading of the tables with coordinates from a file must be made according to the selected type of coordinates. For example, if for one of the tables the geographic coordinates type was selected then the file from which the coordinates are taken from must contain geographic coordinates.

When you type angles in sexagesimal degrees, the separating character can be any of the characters used for the identification of the degrees, minutes or seconds or, you can use space key to automatically introduce it.

A point from table is considered valid only if you introduce its name (point number) and the required coordinates for the transformation. If H or h elevations are omitted then their value is considered 0.000.

In the two tables the point coordinates can be changed. Thus for the ellipsoid of the A system the coordinates can be shown as:
• geographic coordinates (φ, λ, h);
• Cartesian coordinates (X, Y, Z).

For the ellipsoid of the B system the coordinates can be shown as:
• geographic coordinates (φ, λ, h);
• Cartesian coordinates (X, Y, Z);
• coordinates in the projection system (N, E, H).

The settings for the two coordinate systems A and B, ellipsoids and projection system can be made at Options - Parameters calculation Tab.

Epoch of the dynamic coordinates

Enter manually the year with decimals or select the date from the calendar. This box is active only for the 15-parametre time-dependent transformations.

Button Transform →

By using this button the points from the left table are transformed according to the selected transformation method and then written in the right table.

Button ← Transform

By using this button the points from the right table are transformed according to the selected transformation method using the reverse transformation and then written in the left table.

The button is active only for transformations that support reverse calculation using forward transformation parameters.

Information about the way in which the transformations are made can be found at Used Formulas.