| |
What
is OGC?
The Open GIS Consortium, Inc. (OGC) is a member-driven,
non-profit international trade association that is leading
the development of geoprocessing interoperability computing
standards. OGC works with government, private industry,
and academia to create open and extensible software
application programming interfaces for geographic information
systems (GIS) and other mainstream technologies. Adopted
specifications are available for the public's use at
no cost. For more information, visit the OGC web site
at http://www.opengis.org/.
What
is WFS?
The OGC Web Feature Service (WFS) allows a client
to retrieve geospatial data encoded in Geography Markup
Language (GML) from multiple Web Feature Services. WFS
allows for clients and servers of different vendors
to share data without having to convert between proprietary
vendor formats. For specifications on WFS, see http://www.opengis.org/docs/02-058.pdf.
Atlas
and WFS
Currently, Atlas has two WFS servers in operation
in a test mode. First, the Louisiana WFS site at http://atlas0.lsu.edu/la/request.asp
has the Atlas indices for Louisiana and a subset of
the features from the Louisiana GIS CD version. The
USA WFS site at http://atlas0.lsu.edu/usa/request.asp
has the USSampledata warehouse from Intergraph updated
with Census 2000 statistics. For more information about
these WFS servers and the data that they are serving,
click
here.
Please
note: these WFS sites are still in test mode. Expect
changes in these sites as testing progresses.
How
to use WFS with your GIS
The GIS and mapping vendors have not yet enabled
WFS in the initial deliveries of their software. However,
many vendors are providing add-ons, extensions, extended
applications, etc. to give their applications the ability
to use WFS.
| For
Intergraph Geomedia (version 5.1) |
| |
Download
the WFS dataserver as zip file by clicking on WFS_Dataserver_05.01.06.00.zip.
Unzip the contents of this zip file into a temporary
directory and run the setup.exe file. |
| |
|
| For
ESRI ArcGIS |
| |
Visit the ESRI site at http://www.esri.com
for more information. Another source for ArcGIS
WFS support is the Geoleaders web site at http://www.geoleaders.com/. |
| |
|
| For
Mapinfo |
| |
Visit the Geoleaders site at http://www.geoleaders.com/ |
| |
|
| For
other GIS, mapping, and CAD applications |
| |
See
the web sites of their vendors for more information. |
Important
Note:
Since WFS is operating at network speeds, it is
slower than having a dataset stored locally on a hard
drive. A user who uses WFS connections for heavily used
features would be at the mercy of the network. Instead,
users should think of WFS as a way to "try it before
buying it" or, in the case of Atlas, "try
it before downloading it" (since all Atlas data
is free!). Users should use the WFS capability for viewing
features and then downloading all or some of the desired
features. Since some GIS applications, such as Intergraph's
Geomedia, see the WFS features no differently from features
from other data sources, the downloading step is nothing
more than saving the WFS features to a local file. No
need to download a Winzip file from Atlas!
|
|
