Welcome to the gCensus Project!

gCensus leverages the power of Google's free Google Earth application to display its maps. Because of this, you can freely pan, rotate, and zoom into and out of maps, and even change the angle you face towards the ground (from straight down to straight across). Furthermore, you can change the transparency of different areas (or of the whole map) for highlighting or just to see what a particularly interesting region looks like in real life (from Google Earth's satellite imagery).

How do I use it?

To get started, launch the gCensus web interface. Select the data source from which you want to map data in the left-hand pane by clicking on it. After that, just follow the built-in instructions in the right-hand pane to navigate through the application.  In the final step, you'll see a link asking you to "Click here to download your map". When you click on the link, you should allow your browser to open the resulting file with Google Earth. If the browser does not recognize the file as a Google Earth file, then chances are that you need to download and install Google Earth from http://earth.google.com. Once that's done, try clicking the link again and opening the file in Google Earth.

Once your map has opened in Google Earth, you'll see a legend in the upper left-hand corner of the map window; the numbers here correspond to the range of values represented by each color in the map. To see the breakdowns, expand the item named "yourmap.kmz" (or "yourmap-1.kmz", "yourmap-2.kmz", etc.) in the left-hand pane of Google Earth (under "Temporary Places). The subentries let you disable the view of certain data bins or change their transparency. To adjust transparency, just move the slider right below the pane with "yourmap.kmz". For more details on how to use Google Earth itself, please refer to the Google Earth User Guide.

Why?

While working on a project requiring the mapping of Census data, I became frustrated with the Census Department's online mapping interface. I felt that in 2006, we should be able to access dynamic, high-resolution maps and not be restricted to static views and slowly-refreshing map graphics. I also felt that it wasn't reasonable to ask everyone to pay large sums to buy professional GIS packages to get this ability. gCensus is built on software available for free, and thus opens up new possibilities in visualizing geographic data.

Other Frequently Asked Questions

• Why not use the Google Maps API? Why make the user download a separate program?
• While Google Maps is a great application, it just doesn't work this application. It's extremely difficult to draw polygons, and coloring them is out of the question. Google Earth not only allows these, but also allows a much more free-form choice of map perspective, since it is a 3D application.
• Why aren't there any other data sets available?
• Summary File 1 is a proof of concept. Basically, I didn't have time to import any others. Adding data sets is somewhat labor-intensive.
• ...but Summary File 1 isn't even complete!
• Yes — the other problem is that I don't have enough disk space to host the whole thing. Please see the section below on "I'd like to help" if you're interested in the project and can help out.
• Is gCensus Free Software?
• Yes! I haven't gotten around to doing any proper packaging on it (it's a pretty involved application, written in a variety of languages including Perl, PHP, PL/PgSQL, and JavaScript), but my intention is to release it under an OSDL-compliant Free Software license when I can get the time.

I'd like to help!

That's great! gCensus is currently limited by two things:

• Development time
• I'm a full-time student, and can't sink all my time into this project. Hopefully, an open-source release will help fix some of the bugs and add features to the application, but another labor-intensive process is adding new data sources into gCensus. If you're interested in helping out with this, please let me know at the contact email at the bottom of the page.

I think gCensus could be an interesting basis for a research project in geography/demographics or HCI, insofar as its goal is to make public geographic data more accessible to the public at large. These aren't my primary research interests, but if you're interested in working on it (or sponsoring such a project!), please let me know.

To get an idea of the kinds of things we're working on, or to get ideas for a project that you could do, make sure to check out the development blog!

Who are you?

I'm currently a Ph.D. student in computer science at Stanford University. Prior to that , I was an undergrad in Electrical Engineering and Computer Science at the University of California, Berkeley (where I got the inspiration for this project). Although this sort of work is not my primary research interest, it's the kind of interesting thing I like to play around with occasionally. You can find out more about my work at my research home page.

How can I get in contact with you about gCensus?

Send me an e-mail at gcensus@gmail.com.