WMS

WMS (Web Map Service) and WMTS (Web Map Tile Service) are interfaces for retrieving geodata as raster data over the internet. The images are generated by a map server using data from a GIS database.

These images can be used as background maps in OCAD.

• A WMS is calculated on the server side and delivers one image per request.
• A WMTS delivers tiles that have been pre-renderd on the server side, and cached on the client side. The background maps are thus loaded significantly faster by a WMTS service than by a WMS service.

WMS / WMTS requires a georeferenced map. Choose the Scale and Coordinate System command from the Map menu to set the map scale and a coordinate system.
Real world coordinates do not have to be necessarily defined. They can be left at (0/0) for example.

WMS Server

To set up a map from a WMS / WMTS server choose the WMS / WMTS command from the Background Map menu. The WMS / WMTS dialog appears.

The WMS servers are listed in the upper left box of the WMS - Web Map Service dialog.

There are already some preset connections the first time you start the dialogue.

Add a WMS / WMTS Server

1. Click the Add button.
2. The Edit WMS / WMTS Properties dialog appears.
3. Enter the Service, Name of the server, the URL and choose the Version
   If required, also provide a Login with Password, the Token Server URL and a Key.
   You will get these data from the WMS /WMTS provider.

   

4. For WMTS additional information will be shown in the WMTS memory cache.
5. Click the OK button when finished.
6. The WMS / WMTS server appears in the upper left WMS / WMTS server box.

Connect to a WMS / WMTS Server

Select a WMS / WMTS server from the list and click Connect. If the connection was successful, OCAD gets a list from the server with the available layers. These layers are listed in the WMS / WMTS layer table of the WMS / WMTS dialog. Read the WMS / WMTS Layer article to learn how to use layers as Background Maps.

Edit WMS / WMTS Server Properties

Select a WMS / WMTS server and click the Edit button to edit its properties. The Edit WMS / WMTS Properties dialog appears which is equal to the Add WMS / WMTS Server dialog.

Remove a WMS / WMTS Server

Click the Remove button to remove the selected WMS / WMTS server from the list.

WMS / WMTS Layer

Add Selected Layers to Background Maps

After connecting to a WMS / WMTS server the available WMS / WMTS layers are listed in the WMS / WMTS layer box.

1. Select a WMS / WMTS layer in the list and choose an Image format from dropdown list (those formats are provided by the WMS / WMTS server). There is also a Search Field.
2. Choose an option how to add the selected layers:
   • Add Selected Layers as WMS / WMTS Layers to Background Maps (Online)

   

   This is an online Background Map . It is updated by the WMS / WMTS Server by each change of the map view. This can take a moment. Choose the online option only if you are using a fast WMS / WMTS server and work woth high speed internet connection. As an alternative, you can add the layer as an offline background map.

   • Add current view of selected layers to background maps (Offline)

   
   

   • Define the Offline folder. The current map folder is set as default.

   With this offline option an image of the chosen WMS / WMTS layer of the current view is downloaded from the WMS / WMTS server and added as a custom background map to the map. It does not get updated when changing the view.

   • Add User Defined Extent of Selected Layers to Background Maps (Offline)

   
   

   • Define the Offline folder. The current map folder is set as default.
   • Define the Resolution.
   • Define the Extent (minimum easting, maximum easting, minimum northing, maximum northing). The current view extent is set as a default when opening the WMS / WMTS dialog but the entries are not updated automatically by changing the view. The extent can be updated by clicking the Set extent to current view button.

   With this offline option an image of the chosen WMS / WMTS layer of the defined extent is downloaded from the WMS / WMTS server and added as a custom background map to the map. It does not get updated when changing the view.

3. Click the Add button.

   The WMS / WMTS layer appears in the table of the Manage Background Map dialog which can be displayed in the Background Map menu.

   The Background map (Geo-Referenced) dialog appears if no real world coordinates offset is set. Choose an offset and click the OK button.

Web Map Services generally provide their images in multiple spatial reference systems. OCAD can only access to WMS / WMTS if the OCAD maps' coordinate system (ex. Swiss Grid CH1903+/LV95) is supported by the WMS / WMTS. Then the Spatial reference system is automatically set to the corresponding EPSG code. If the chosen coordinate system is not compatible with the WMS / WMTS, the Spatial reference system caption in the WMS / WMTS dialog remains empty.

Click the Close button when finished.

Remove Selected Layers from Background Maps

To remove a WMS / WMTS layer or to manage its view, choose the Manage command from the Background Map menu:

WMS Examples

WMS layer indicating forest reserves that may not be entered.


WMS layer that contains cadastral survey data.