Geospatial Semantic Web Blog

Geospatial Web and Semantic Web are two major discussion topics of the Social Web Technologies course. In the past few classes, we talked about GIS, Google Maps API, geotagging and Geonames.

When introducing Geonames to the students, I decided to do a little experiment. I used Geonames as a tool to teach students the basics of GIS and provide them an opportunity to experience a “social-able” Geospatial Web.

An Annotation Competition

The experiment was relative simple. I spent few minutes introducing Geonames to the students. And then, I asked them to play a game. The class was divided into two teams: Team1 and Team2. Using Geonames, the teams competed with each other in identifying landmarks, buildings and roads that are located within the close vicinity of the UMBC campus. Each student signed up for a free Geonames user account. Using the wiki-style annotation tool provided by Geonames, students tried to annotate as many spatial features as they can in 10 minutes. The team produced the most annotated features would win.

To keep track of the features that each team had annotated, students were asked to tag their features using their team ID: “team1″ and “team2″. Using the Geonames search tool, I displayed the real-time progress in front of the class.

• Features identified by Team1
• Features identified by Team2

Lesson Learned

• It’s fun to use Geonames in a collaborative environment. Students enjoyed the process of creating annotations while chatting with each other and arguing about the location of a specific landmark. It was a social-able experience.
• Geonames has a relative open policy for users to make contributions — whatever the user enters, Geonames stores it. In general, this is a good thing. However, this policy can also lead to unintended creations of duplicated data. For example, because students were entering data simultaneously, we frequently saw multiple annotations of the same location were entered and they had different coordinates values assigned.
• It seems that using the Web as a platform can encourage non-GIS experts (e.g., students) to do GIS tasks (e.g., annotation). Not sure if this is an inherent feature of the Web or just because of the UI of Geonames is well designed.

Geonames announced a new experimental service that includes thumbnail images of geographical locations in its query results. For example, a search query to lookup London UK will return a thumbnail image of London. All thumbnail images produced by Geonames are acquired from various geographical location pages on Wikipedia.

Marc at Geonames Blog introduces this new feature:

Thumbnail images for wikipedia articles are a new experimental addition to the geonames webservices, the full text search and the maps mashup. Around a third of all articles on geonames have thumbnail images. A simple algorithm determines which image to use as thumbnail if more than one image could be parsed from the original article.

I think this new feature could be useful to many Web mashup applications, especially those that need to display photos of some arbitrary geographical locations — maybe in a semantic-web travel tool.

Geonames.org is a popular GIS web service built on the simple REST framework. Not only it’s excellent platform for building innovative web applications that require access to GIS data and geocode services, but also it’s a poor man’s solution to ArcGIS Server (sort of).

A Java API for accessing Geonames web service has been released. Check out the project page at its SF.net page. Look at this page for a quick code example. If you need more information, see its Javadoc page.

Geonames.org is an excellent web site for one-stop shopping of geospatial data. It features about 2.2 million records of geographical information. This includes data from

• NGA Geographic Names Database (GNDB)
• NGA US Board on Geographical Names
• U.S. Geological Survey Geographic Names Information System
• GeoBase data of Canadian geographical feature names
• Wikipedia, elevation of mountains, world population data etc.

Many reasons why Geonames.org is interesting: Read the rest of this entry »