Create, edit or delete custom Coordinate Reference Systems (CRS)

In this latest version of the jCRS extension, users can define a custom CRS. This functionality is available through the CRS selection dialog, see figure 14.

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Figure 14: Selection of a user-defined CRS

When selecting User CRS as the type of CRS, you can choose from the following options:

  1. Choose a custom CRS that was previously defined, by selecting it from the table and click on OK. To facilitate the selection when there are many user-defined CRS, there are two search options to find common CRS: by code and by name.
  2. To find information on the selected CRS, you can click on the CRS info button, after which a window with the available information will appear.
  3. To edit the selected CRS, click on the Edit button. A dialog with different tabs will appear which is similar to the dialog in which you can define a new custom CRS. These dialogs will be described later on in this document.
  4. To delete the selected CRS, click on the Remove button.
  5. Create a new custom CRS, as described here below.

To create a new custom CRS, click on the New button in the dialog shown in Figure 14, after which the dialog User defined CRS will open (see figure 15) to guide you through the process of creating a custom CRS.

This dialog includes three tabs:

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Figure 15: Create a new custom CRS

By clicking the button Next you can move from one tab to the next.

In figure 16, the panel of the Datum tab is shown. In this tab, the following information must be filled:

The default ellipsoid and meridian for user defined CRS are the GRS80 ellipsoid and Greenwich meridian.

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Figure 16: Definition of the datum for the CRS

When the datum parameters are defined, the Coordinate system information associated with the CRS must be filled in the next tab as shown in figure 17.

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Figure 17: Selection of the coordinate system for the CRS

The following Coordinate system information must be filled:

To edit a custom CRS that was previously defined (see figure 14), select this CRS from the table and click on Edit.

Below in figure 18 the dialog Definition of a new custom CRS is displayed, where the tab User CRS is disabled as well as the CRS code in the Datum tab. The reason why you can not modify the CRS code is that this code is used for the indexation of the user database. The other values for the datum are editable, as well as the values for the Coordinate system tab (see figure 19).

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Figure 18: Editing of the datum values

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Figure 19: Editing of the coordinate system of the CRS