Latitude-Longitude Projections

The latitude-longitude projection format (LatLonProjection) in the Terrain Images.cfg file is defined by four parameters for latitude and longitude.

To specify a LatLonProjection for unprojected images (raw unprojected bitmaps and general images, unprojected), you can enter settings for the LatLonProjection within the Terrain Images.cfg window in data workbench. See To specify a LatLonProjection for unprojected images.

To specify a LatLonProjection for images with embedded projection information, you must open the Terrain Images.cfg file in a text editor such as Notepad, set the Projection Info parameter to “LatLonProjection”, and add settings for the LatLonProjection. See To specify a LatLonProjection for images within embedded projection information….

• To Specify a LatLonProjection for Unprojected Images
• To Specify a LatLonProjection for Images Within Embedded Projection Information…

To Specify a LatLonProjection for Unprojected Images

1. Open the Terrain Images.cfg file in data workbench and add a terrain image layer source as described in To define a terrain image layer.

2. Edit the Projection Info parameters using the following parameters table as a guide:

   Parameter	Description
   Lat0	The latitude of the top edge of the image, in degrees, where 90 is the North Pole and -90 is the South Pole.
   Lat1	The latitude of the bottom edge of the image.
   Lon0	The longitude of the left-hand edge of the image, in degrees, where positive numbers are east and negative numbers are west longitudes.
   Lon1	The longitude of the right-hand edge of the image.

3. Save the file by right-clicking (modified) at the top of the window and clicking Save.

4. To save the locally made changes to the data workbench server machine, in the Server Files Manager, right-click the check mark for Terrain Images.cfg in the Temp column, then click Save to > < server name>.

To Specify a LatLonProjection for Images Within Embedded Projection Information

1. In the Server Files Manager, click Components to view its contents. The Terrain Images.cfg file is located within this directory.

2. Right-click the check mark in the server name column for Terrain Images.cfg, then click Make Local. A check mark appears in the Temp column for Terrain Images.cfg.

3. Right-click the newly created check mark in the Temp column and click Open > in Notepad. The Terrain Images.cfg file appears in a Notepad window.

4. Edit the Projection Info parameters using the following sample file fragment as a guide. Be sure to specify the projection type as highlighted below. For descriptions of the parameters, see the LatLonProjection Parameters table in the previous procedure.

   Projection Info = LatLonProjection:
     Lat0 = double: 90
     Lat1 = double: -90
     Lon0 = double: -180
     Lon1 = double: 180