Difference between revisions of "WMS"

From OCAD 12 Wiki - English
Jump to: navigation, search
(Add Current View of Selected Layers to Background Maps (Offline))
(Add Current View of Selected Layers to Background Maps (Offline))
Line 67: Line 67:
  
 
Examples to display the map:<br />
 
Examples to display the map:<br />
 +
 +
 
[[File:WMSExample.PNG|1000px]]<br />
 
[[File:WMSExample.PNG|1000px]]<br />
 
[[File:WMS4.png|1000px]]
 
[[File:WMS4.png|1000px]]

Revision as of 10:45, 14 August 2012

A Web Map Service (WMS) is a standard protocol for serving georeferenced map images over the Internet. The images are generated by a map server using data from a GIS database. (taken from the Wikipedia Article.)

Hint.jpg WMS 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.

To set up a map from a WMS server choose the WMS - Web Map Service command from the Background Map menu. The WMS - Web Map Service dialog appears.

WMSDialog1.PNG

WMS Server

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

Add a WMS Server

  1. Click the Add button.
  2. The Add WMS Server dialog appears.
  3. Enter the Name of the server, the URL, the Version and, if required, a Login with Password, the Token Server URL and a Key.
    AddWMSServer.PNG
  4. Click the OK button when finished.
  5. The WMS server appears in the WMS server box.

Connect to a WMS Server

Select a WMS 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 layer table of the WMS - Web Map Service dialog. Read the WMS Layer article to learn how to use layers as Background Maps.

WMSDialog2.PNG

Edit WMS Server Properties

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

EditWMSServerProperties.PNG

Remove a WMS Server

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

WMS Layer

After connecting to a WMS server the available WMS layers are listed in the WMS layer box. The Image format can be chosen if a layer is selected.

WMSDialog3.PNG

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


Add Selected Layers as WMS Layers to Background Maps (Online)

Select a WMS layer in the list, choose an image format in the Image format dropdown list (those formats are provided by the WMS server) and click the Add selected layers as WMS layers to background maps (online) button. If no real world coordinates are set, the Background map (Geo-Referenced) dialog appears. Choose an offset and click the OK button.

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

This is an online Background Map. Everytime the view of the map is changed, the Background Map gets updated from the WMS server. Updating the Background Map can take a moment. Choose the online Background Map option only if you are using a fast WMS server and a good internet connection. As an alternative, you can load the layer as offline Background Maps.


Add Current View of Selected Layers to Background Maps (Offline)

Select a WMS layer in the list, choose an image format in the Image format dropdown list (those formats are provided by the WMS server) and click the Add current view of selected layers to background maps (offline) button. If no real world coordinates are set, the Background map (Geo-Referenced) dialog appears. Choose an offset and click the OK button.

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

This is an offline Background Map. An image of the chosen WMS layer of the current view was donwloaded from the WMS server and is now available in OCAD. The Background Map does not get updated when changing the view.


Click the Close button when finished. You can manage the view or remove the WMS maps by choosing the Manage command from the Background Map menu.

WMSBackGroundMap.PNG

Examples to display the map:


WMSExample.PNG
WMS4.png