Resource Mapping

Tuesday, February 27, 2007

Using OGC Web Map Services in your BLOG

What is an OGC Map Service?
When you start your course you are going to hear a lot about GIS Standards and Interoperability and the word OGC will crop up. Almost all of the major web-map development has in some way addressed OGC. An OGC architecture is firmly rooted in virtually all of the Open or Freely available GIS applications plus some propriety applications.

OGC defined

“The Open Geospatial Consortium, Inc.® (OGC) is a non-profit, international,voluntary consensus standards organization that is leading the development of standards for geospatial and location based services.”

The OGC is a consortium of 338 companies, government agencies and universities which in a participatory way are defining a set of development standards to spatially-enable the Internet and wireless environments for providing location-based services. It therefore represents an “Open” system to promote spatial technology in all walks of life. Of utmost importance was interoperability which in simple terms means a common platform for displaying and sharing spatial information. Also important was ease of deployment , with the OGC literature describing “plug and play” implementation of geo-processing applications.

OpenGIS® is a Registered Trademark of the Open Geospatial Consortium, Inc (OGC) and is the brand name associated with the specifications and documents produced by OGC.

What are OpenGIS Specifications?

Firstly these are freely (at no cost) available technical documents that describe interfaces and coding standards. Spatial programmers will use this documentation to develop (from the basic architecture through to the interface) their geo-spatial products and services. The specifications within this documentation are the main OGC product and are based on the contributions of its various members. There is a set of specifications for implementation that accompanies the abstract specifications. These are aimed at more technical users and articulate the interfaces between various software components. Varieties of schemas (xsd, xslt, etc) are approved for support in developing various spatial software applications. In contrast to the very technical implementation specifications the abstract specifications provide a conceptual foundation based on OGC specifications. In addition to these specifications there are discussion documents that are produced by the various Working Groups within the OGC, but these are not necessarily used for endorsement or implementation. If you want to go into this subject area in more detail I suggest you view their site, which is where I got this information.

The influence of OGC on the spatial technology industry

Almost all of the major software developers have taken note of OGC, while some simply make their products OGC compliant, others have taken the initiative further. We have used an OGC Web Map Services from the Demis software provider ( in developing the interactive maps for the Global Invasive Species Programme ( One of the advantages was a really well packaged global base map that came with the application.

To view our OGC Web Map Service, you will need Shockwave to be installed. If correctly installed, you will see part of the world with Africa in a central and prominent place.

You can also put an OGC Interactive map in your application or BLOG. You simply need to insert the following code and this will extract the Web Map Service (WMS) from our OGC server.

<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
flash/,0,0,0" align="middle" height="450"

<param name="_cx" value="14367">
<param name="_cy" value="8890">
<param name="FlashVars"
<param name="Movie"
<param name="WMode" value="Opaque">
<param name="Play"
<param name="Loop" value="0">
name="Quality" value="Low">
<param name="SAlign" value="LT">
<param name="Menu" value="0">
<param name="Base"
<param name="AllowScriptAccess" value="always">
<param name="Scale" value="NoScale">
name="DeviceFont" value="-1">
<param name="EmbedMovie"
<param name="BGColor" value="CCFAFF">
<param name="SWRemote" value="">
name="MovieData" value=""><embed
loop="false" menu="false" quality="low" scale="noscale" salign="LT"
wmode="transparent" devicefont="true" bgcolor="#CCFAFF" swliveconnect="true"
id="MapClip" type="application/x-shockwave-flash"
pluginspage="" align="middle"
height="450" width="440"></object>

  • You will need to remove any spaces in the URLs for the code to work (I had to put a space in some urls to force a wrap around to fit in the main blog window).
  • You can change which part of the world you are viewing by changing the parameters in the Boundary Box ~ BBox=-80,-90,80,90.
  • The above parameters will produce a map from the North Pole to the South Pole and from 800E to 800W.
  • Remember a negative Latitude occurs in the southern hemisphere, and a negative Longitude occurs west of Greenwich. Using a width of 440 will fill Blogger's main frame.
  • It would be best to copy and paste this code into Notepad to ensure that no formatting has been copied and then examine each URL to remove spaces and finally you can modify your map size and Boundary Box parameters to suit your site and intended map view.

Here is a map showing just Spain using the Boundary Box parameters of -10,35,5,45.

Feel free to pull some maps from our OGC web map services. Explore the floating Map Menu - if you click on the (i) button and then double click on a country it will take you to information on invasive species for that country. You can turn on and off layers of information, maximize your map to the entire world, as well as pan and zoom. Enjoy the freedom of OGC web-maps.