• DATA RESOURCES ON THE INTERNET •
In the bad old days, GIS data was distributed on disk. Today the Internet is the primary route for getting spatial data to users. The Biodiversity Center makes extensive use of download portals to obtain data items for our own use. We are also beginning to incorporate Internet map services into our work. We've documented a lot of what we've learned about locating and using Internet data resources. We believe that our efforts in this regard help our students and collaborators get their projects off to a faster start than would otherwise be possible.
Download Portals
Many State and Federal agencies operate download portals whose purpose is to get their spatial
data out to the geospatial technology community. We've made extensive use of these sites to stock our library.
Internet Map Services
GIS servers are set up by data owners to allow their data to be accessed directly. Desktop users connect
to the data across the Internet. Once connected, they can add layers called "map services" to desktop sessions
(more info).
GIS servers and map services greatly reduce the need for distributing many copies of popular datasets. It is a very efficient
approach to data distribution and appears to be where the world is headed. As the technology evolves, more and more data is
distributed this way and traditional approaches to data distribution are starting to go away.
It should be noted that adding a map service to an ArcGIS desktop session is a little different from most "Add Data" operations.
Before the individual service can be added, a connection to the server must be made in ArcCatalog.
Connecting to a server is accomplished by typing or pasting a string of text into a text box.
Information on the nuts and bolts of connecting to map services can be found at:
•
Connecting to GIS servers
(tutorial available at the ArcGIS Help Library hosted by Esri)
•
How to Connect to an
ArcIMS map service (tutorial hosted by Pennsylvania Spatial Data Access)
•
How to Connect
(tutorial hosted by Otter Geospatial)
Suggested Websites & Wikis
USGS Seamless Data Warehouse. Map services hosted by USGS are listed at
http://seamless.usgs.gov/services.php
ArcGIS Resource Center. Maps and tasks hosted by ArcGIS Online are listed at
http://resources.esri.com/arcgisonlineservices/index.cfm?fa=content
Otter Geospatial. Selected download portals are listed at
http://www.ottergeospatial.info/download-portals.
Selected map services are listed at
http://www.ottergeospatial.info/map-services
Suggested Articles & Reports
Göçmen, Aslı and K. Van Gilder, 2010. Handbook of Web-based Environmental Data for Wisconsin's Planners.
The report is available for download at
http://urpl.wisc.edu/people/gocmen/environmentalgeospatialdata.pdf
Wisconsin Coastal GIS Applications Project, 2009. Wisconsin County and Municipal Web Mapping Sites.
The report can be viewed at
http://coastal.lic.wisc.edu/wisconsin-ims/wisconsin-ims.htm