In this section you can perform coordinates transformations from one system to another by introducing the coordinate operations at your choice.

When installing, the transformation model Stepwise is implicitly loaded, this models description of transformation can be found at Recommendations.

Transformation models

In this box you can define transformation models with their coordinate operations.

The contextual menu that appears in this box by right click on the mouse contains the following commands:

Add a model / coordinate operation

Add a transformation model or a coordinate operation;

Cut model / coordinate operation

Delete and copy to Clipboard memory the selected item;

Copy model / coordinate operation

Copy to Clipboard memory the selected item;

Paste model / coordinate operation

Insert a new item with the contents of the Clipboard memory;

Delete

Delete the selected item;

Rename

Rename the selected item;

Expand all ...

Expand all nodes of models list;

Collapse all ...

Collapse all nodes of models list;

Locked

Lock or unlock the selected model;

Support reverse calculation

Show if the selected model or operation supports or not reverse calculation;

Invertible model / coordinate operation

Show if the selected model or operation is invertible or not;

Domain ...

Shows the applicability domain of the selected operation, it depends on the type of calculation and can be 2D, 3D or both;

Invert model / coordinate operation

Reverse the calculation sense for the selected model or operation. In the case of a transformation model all its operations and their order are reversed;

Check the model validity

Check if the sequence of the coordinate systems is correctly set for the selected model, from the initial system through all coordinate operations systems to the final system;

Model / Coordinate operation properties

Editing properties for the selected model or operation.

Button [▲]

Change the position of the selected item (transformation model or coordinate operation) by moving it up.

Button [▼]

Change the position of the selected item (transformation model or coordinate operation) by moving it down.

Note: The change of the position of a model or of a coordinate operation can be made by using the procedure of drag and drop with the mouse within the list of transformation models.

Button Add a model

By using this button you can add at the end of the list a new transformation model. The description of this windows can be found at Add a new transformation model / Transformation model properties.

Note: Select with care the type of coordinates for the initial and final coordinate system because at the beginning of the calculation the coordinates will be taken from the table on the left according to the coordinates type declared at the initial system and at the end of the calculation the results will be shown according to the type of coordinates declared at the final coordinate system.

Button Delete model

By using this button you can delete from the list the selected model. For this action a confirmation of deletion is asked for.

Caution: The model that was deleted can’t be recovered.

Button Model Properties

By using this button you can edit the properties of selected model. The description can be found at Add a new transformation model / Transformation model properties. The editing can also be made by double clicking with the mouse on the transformation model icon.

Button Add a coordinate operation

By using this model you can add at the end of the sub-list of the selected transformation model a new coordinate operation. The description of the window can be found at Add a new coordinate operation / Coordinate operation properties.

Note: For a correct calculation choose for the first step the input coordinate system which is identical with the initial coordinate system declared at the transformation model. The same must be done for the last step in which the output coordinate system must be identical with the final coordinate system also declared at the transformation model. Please note that the program does not verify this selection, it remains in the task of the user to do this check.

Button Delete coordinate operation

By using this button you can delete from the sub-list the selected coordinate operation. For this action a deletion confirmation is asked for.

Caution: The coordinate operation that was deleted can’t be recovered.

Button Coordinate operation properties

By using this button you can edit the properties of the selected coordinate operation. The description can be found at Add a new coordinate operation / Coordinate operation properties. The editing can also be made by double clicking with the mouse on a coordinate operation.

Button Save model to file

By using this button you can save in a file the selected transformation model.

Button Save all models to file

By using this button you can save in a file all models from the list.

Button Load models from file

By using this button you can load one or more transformation models from a file. The models taken from a file are written at the end of the list.

Button Upload model on www.topolt.com

By using this button you can upload in the database from www.topolt.com the selected transformation model. To publish on the Internet the model you have created it is necessary to login.

The description of the window can be found at Upload or edit transformation model window.

Button Download model from www.topolt.com

By using this button you can download from the database from www.topolt.com a transformation model published by you or another users. To download a model it is not necessary to be login.

In this window you can also update models published by you. The description of the window can be found at Download or update transformation model window.

Button Create a model using the EPSG database

By using this button you can add a transformation model that is obtained by selecting a route between two coordinate reference systems (CRS) from the EPSG database. The route between two CRSs is given by the operations with coordinates defined in the EPSG database. The description of the window can be found at The window of creating a new transformation model from the EPSG database.

Transformation test

Buttons Test for first point

With this buttons you can make a transformation test for the first point from the left table or from the right table (depending on the direction of the calculation). The report presents step by step the calculated values, thus you can check the calculations made and the correctness of the steps declaration.

In addition, for round-trip calculation, the differences between the initial point coordinates and the coordinates calculated by applying the transformation in either direction are displayed.

Coordinate 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 by respecting 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.

Button Download altitudes using Google Maps Elevation API services

This button is available only when in the table there are geographical coordinates defined on the 3D domain. Clicking this button opens the window Download altitudes using Google Maps Elevation API services.

Warning: To obtain these altitudes accurately, it is necessary that the points from the table to be in the geographical coordinate system defined on the ellipsoid "WGS84" ("ETRS89"), Prime Meridian "Greenwich". It's up to you to do this verification.

Button Draw points from table in Google Earth

By using this button you can draw points from table in Google Earth. This button becomes active only if the table contains geographical coordinates (φ,λ,h).

After requesting from menu one of the drawing modes, the window Draw in Google Earth is opened to do the drawing.

Button: Transform →

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

The button is active only for the transformation models that support reverse calculation.