Web Mapping Service

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Web Mapping Service

The Web Mapping Service (WMS) standard offers a great way to access maps and aerial photos from online WMS compliant servers. There are paid servers, but many states provide access to maps and aerial photos at no cost via WMS.

 

View a training video on Web Mapping Services in EnviroInsite here.

 

Select Insert> Web Map Service from the main menu to open the Web Mapping Services dialog box. The first thing to do is to select the WMS server from the Layers tab. Next, go through the Layers tree control and select the individual layers to display. Finally, go to the Bounding Box tab and set the pixel size so that the pixel width and height does not exceed 2000.

 

WMS images will automatically be georeferenced to either UTM or State Plane coordinates. The destination coordinate system is selected from the View Options dialog box. Select View> Options from the main menu to open the View Options dialog box. Be sure to select the State Plane zone or the UTM zone and set the hemisphere as northern or southern before trying to insert a WMS image.

 

Layers Tab

 

50089-layers_tab

 

WMS URL - Contains the URL address for the WMS servers. Either select one of the default URLs in the WMS dialog box or enter another URL into the row with the star at the bottom of the URL list. After entering the URL, hit the header column to the left and a layer list will be generated in the list box below.

 

Layers - The layer list is generated to show the layers in the selected WMS URL. Each layer is listed, along with all of the available format styles. Place a check box next to the layers to display. Only one WMS URL can be selected in each WMS plot object. To access layers from other URLs, simply create another WMS object by selecting Insert> Web Map Service.

 

Bounding Box Tab

 

50089-bounding_box_tab

 

Pixel Size

 

This is the pixel size in meters. The smaller the pixel size, the more detail you will see in the image. Typically, there is a limit in the pixel size of images that servers will download and is often about 2000 pixels wide or high. If after leaving the WMS dialog box, the image does not appear, try increasing the pixel size to reduce the number of pixels.

 

Coordinates of the Bounding Box

 

These coordinates will be used in the request for a map image. Select the Update button to automatically set the coordinates to bound the current view.