Select Coordinate Systems
Use the Select Coordinate System dialog to choose a pre-defined coordinate system, to define a new coordinate system, to customize an existing coordinate system, or to copy a coordinate system string to the clipboard.
- The Selected Coordinate System table is populated with the coordinate system information from the input dataset. To choose a different coordinate system, click to expand the lists of Geographic Coordinate Systems or Projected Coordinate Systems (or, use the Search field to search for a given coordinate system), then select the specific coordinate system. Its properties display in the Selected Coordinate System table.
Tip: WGS 1984 is located under the Geographic Coordinate Systems > World folder.
- To define a new coordinate system, click the Create New button . The Edit Coordinate System dialog appears. Here, you will define the details of a projected coordinate system, which includes properties of a geographic coordinate system plus a map projection type, projection parameters, and projection units.
In the Edit Coordinate System dialog, click Select to choose a geographic coordinate system. Then choose a projected coordinate system Type and Units from the drop-down lists provided. Enter a Name for the new coordinate system, then click OK to return to the Select Coordinate System dialog.
- If you frequently work with a specific coordinate system, select its name and click the Add Favorite button . The coordinate system is added to the "Favorite Geographic" or "Favorite Projected" folder in the Select Coordinate System dialog. You can also select custom coordinate systems as favorites, and favorites can have duplicate names. To remove a coordinate system from either folder, select its name and click the Remove Favorite button .
- To use the same coordinate system as another dataset, click the Import from Existing Dataset button and select the source dataset.
- Each coordinate system is represented by a text string that describes its properties for use with ENVI programming and header files. See Coordinate System Strings and Codes for details. To retrieve the text string, select a coordinate system name and click the View as String button . Copy and paste the string into your application where needed. Or, click the Copy String to Clipboard button .
- To edit the projection information of a coordinate system that you already selected, click the Modify Existing button . The Edit Coordinate System dialog appears with the projection details populated. Modify the geographic coordinate system and projected coordinate systems as needed.
Note: The edits only apply during the active session and are not permanently saved. To save your edits, add the edited coordinate system as a favorite.
Map Information in ENVI, Working with Map Information in the ENVI API