GeoRSS Weblog

Jason Birch has a nice little tutorial on building a GeoRSS feed to show current housing starts with a feed of new construction building permits. He’s using Safe Software’s FME, but even if you don’t have that, he also shows the output on Google Reader and Google Maps. Very nice!

Announced on the Google Maps Blog, GeoRSS, in all its glory, is now supported by Google Maps. Support for KML has been vastly improved too.

Maybe it doesn’t need to be said, this is a big big deal for GeoRSS. We now have support across all three major web map apis, and a common language for geospatial web.

There are some samples on the GMaps blog. Here’s another. Hmm, the documentation example itself isn’t working; that one is requesting a flickr GeoRSS feed .. perhaps Y is throttling, as Google will need to proxy all GeoRSS API requests through its own servers.

Anyway, now looking forward to GeoRSS in Google Earth. But not before a little celebration. Congrats all and cheers Google!

This article in Information Week on map mashups in business highlights GeoRSS, and illustrates with a mashup created by BP of their assets in the Gulf of Mexico post-Katrina, apparently using some GeoRSS feeds.

Yahoo Pipes, the new RSS remix and mashup programming environment from Yahoo has made a stunning debut. I’ve used Ray Ozzie’s quote “RSS is the Unix Pipe of the Internet” in my presentations on GeoRSS, and Pipes is a big step towards realizing that idea .. this kind of leveraging of RSS is exactly the reason why it’s a good idea to package up geography in GeoRSS.

And GeoRSS is pretty central to the new service. O’Reilly’s Brady Forrest deconstructs a location based pipe. Chris Schmidt has added GeoRSS output to MetaCarta Web Services to integrate with the Pipes system.

I’ve made some experiments with Pipes, and reported them on my weblog. There are still a lot of rough patches, see the section on GeoRSS in my blog post for some specific bugs and gotchas. But it’s a promising start and the developers seem to be listening closely to feedback, so feel encouraged to have a try.

For those who know what a coordinate reference system (CRS) is, move along to the next paragraph. But for the curious, here’s a quick lesson in coordinate reference systems. The one everyone knows is that used by Global Positioning System satellites, which uses latitude and longitude coordinates expressed in decimal degrees and tied to the reference system and model of the shape of the earth known as WGS84. This is the default CRS for GeoRSS. It works OK for a global standard, but the accuracy is only plus or minus a meter, which just doesn’t cut it when you’re building a bridge or surveying property lines. So engineers often use CRSes that are accurate to inches or better, using models that maximize accuracy for one small part of the world, but are worse than even WGS84 when you move to other areas.

GeoRSS GML has always supported CRSes other than WGS84 lat/lon (which is the default for both GeoRSS Simple and GML), but until now we’ve been extremely lazy and haven’t had any examples of how to specify a CRS. Guilt has overcome laziness finally and I’ve gotten one example posted here (ignore the fact that the coordinates don’t make sense for CRS urn:ogc:def:crs:EPSG:6.6:26986, which by the way is Massachusetts Mainland Stateplane meters–maybe I’ll fix that by 2008).

Safe Software, makers of FME, a professional GIS tool for transforming and translating geodata formats have announced support for GeoRSS. And it’s very comprehensive .. for reading, writing, all the various flavors, and a thorough introduction for FME users. They’ve even shown quick demos on Mapufacture and mylocalguru. Check it out. Well done.

FME has supported development of GDAL/OGR in the past. So maybe GeoRSS support there is coming too?

Thanks to All Points Blog for the tip. And while GeoRSS may not be “approved”, we definitely think it’s “safe”.

I’m not sure why I had not noticed this before, but Jeremy Cothran has been working on ObsRSS and now, ObsKML as a means of managing geographically oriented observations from ocean observing platforms (i.e. buoys).

(Note that the links above will result in showing you some login dialogs. Just click “Cancel” twice and you can still see the pages.)

Dan Karran has been busy adding GeoRSS & KML support to Drupal 5.

He’s looking for feedback on bugs and additional features - so give it a try and let him know.

Yahoo! Research Berkeley is datamining the 10 million+ geotagged flickr photos (all available in GeoRSS btw), and particularly deriving meaning from the association of geotags and folksonomic tags. Particular words become associated with particular places, and that’s interesting and potentially useful. Yahoo explains it better.

How’s this new development relate to GeoRSS? The World Explorer data is available through an API which returns GeoRSS. And the TagMaps visualization tool reads data in GeoRSS. A nice input output cycle of GeoRSS.

Interestingly, this touches on a recent GeoRSS list discussion on how to apply styling to GeoRSS. Though we concluded that GeoRSS should focus on data without styling, I did note the worldKit associates different styling options (like color, size, and opacity) with the field. Similarly, TagMaps uses the category to set the size of each tag. So, a potentially useful “in the wild” convention.

I’ve written up some critical feedback of the new-ish GeoRSS features Yahoo introduced in September.
The short of it: Polylines and Export are great. But we’d like to see Yahoo support and default recommend GeoRSS Simple and GeoRSS GML.