Posts Tagged GeoRSS
GeoRSS and Google Maps for Fire Response Notifications
Posted by Jason Birch in Formats, Google, Nanaimo on February 18, 2008
One of the developers in my section (Chris McLuckie) has been working on a replacement for our creaky old fire incident notification system, and launched the new City of Nanaimo Fire Daily Calls page last week. If you’re interested, you can read the official press release (pdf).
Basic improvements include:
- automatic pull from our FDM Computer Aided Dispatch (CAD… a popular acronym) database, removing requirement for dispatchers to manually update this list
- publication of the incidents in multiple formats (GeoRSS, HTML… KML planned for an intermediate update)
- integration with Google Maps
This is what the query interface for incidents looks like:
This is the embedded Google Map (using the GGeoXML class to hit the GeoRSS feed) showing incidents for the selected day:
This is the basic statistics interface allowing users to see incident activity for a date range (which also has a similar Google Map embedded):
And this is what the GeoRSS feed looks like in Google Maps
And now for the technical stuff…
Chris has put together a fairly strong process for extracting and displaying this information publicly, consisting of several components:
- A monthly FME process that reads the current 9-1-1 streets shape file and places it into a normalized database structure (one-to-many between lines and coordinates). This allows easy formatting of coordinates for different output formats (GeoRSS, KML, etc) in native ASP.Net.
- A SQL Server Integration Services job that pulls initial incident data from our CAD database, as well as updated information from the RMS (records management system), generalizes it to block ranges to reduce privacy concerns, and writes it our publicly accessible webserver.
- An ASP.Net web application that transforms an XML serialized data set into GeoRSS (and eventually other formats) using XSLT.
- An ASP.Net web application that provides the rudimentary user interface, including the incident query mechanism, incident statistics, and Google Maps integration.
The current applications are accessed via IFRAMEs because although our standard for web apps on our main site has changed from ASP to ASP.Net, our web site migration is still under way. Once the web site is redeveloped, these will be standard non-encapsulated web apps.
This is definitely just a starting point for us; the framework that has been used for this application was designed so that we can add other data sources that make sense for GeoRSS syndication, such as recent business licenses, building permits, etc. This aligns with our website redevelopment, where we are using RSS/Atom as an alternate access mechanism wherever possible.
As an initial project, there are certainly limitations with this implementation. For instance, we haven’t defined an API for pulling down specific categories or date ranges from the RSS feed. Also, because the GGeoMap class doesn’t expose properties of specific features, we were unable to link the incident rows with the map (pan and pop-up). There are third-party interfaces to Google Maps (GeoXML, EGeoXML) that work around this, and of course the option of just creating the lines ourselves, but we were trying to keep coding and dependencies to a minimum. There is a ticket in the Google Maps API issue tracker for this, so hopefully it will be addressed eventually…
Ideally we’d be using a spatially-enable database (such as PostGIS) as the underlying data store for this application, but we don’t have PostGIS in place on our public webserver yet.
-J
GeoRSS: FME Rocks My World Again
Posted by Jason Birch in FME, Google, Tutorial on March 26, 2007
There’s a simple indicator I use to tell when I’m too busy at work; it’s called the FME scale. Any time it takes me over a month to play with a new feature in Safe Software’s FME, I’m swamped :)
In this case, it was particularly painful. I’m really interested in GeoRSS because I see the potential that it has for increasing the level of information my municipality can deliver to its residents. For instance, we could offer insight into current housing starts with a feed of new construction building permits.
For me, the beauty of GeoRSS is that it has value even without the maps. With a single format, I can publish information that our residents can view in their favourite feed reader, while allowing more sophisticated users to benefit from the spatial information.
As you can see from the following screenshots of a GeoRSS file displayed in Google Reader and Google Maps, I’ve finally found a little time to play around with the GeoRSS support in FME. You can click on the second image to see how it works. Keep in mind that the data is static, and not guaranteed to be accurate for any use:
Until now, much of the GeoRSS that I’ve had a chance to look at has been point-based, so it’s nice to have a way of generating some more complex elements in Simple and GML varieties and, now that Google Maps supports GeoRSS, an easy way to visualise it.
So anyway, how did I generate this GeoRSS file? It was pretty easy, and I’ll take you through the steps.
First, I had to set some basic parameters for the feed in FME. This image shows the basic workflow, from create a single feature with no geometry, through to writing the feature out to the “Feed” output:
Inside of the AttributeCreator, I’m setting some basic values for the feed as a whole:
Pretty simple, eh?
Next, I pull in some data from our property records database, and merge it with an Oracle Locator spatial table which holds the City’s parcel base:
And finally, I set the same the entry-specific GeoRSS parameters, this time using attributes of the building permit records instead of static text to fill in the blanks:
And that’s all she wrote. I still have to find time to fine-tune some of the attributes (such as dates and link), get some approvals, and work out the logistics of getting the data out to our external server nightly. It sure is nice that the technical part is so easy though.
If you deal with spatial data on a regular basis and haven’t evaluated FME, you’re doing yourself a disservice. Pick up the latest beta from their site (for GeoRSS support), request an evaluation license, and play around a bit. Everyone’s usage pattern is different, but I was able to justify the cost of my initial license and training with the time it saved over about six months. Safe Software deserves a lot of credit. Apart from the usefulness of FME, their support is incredible. They are the only company that I have ever dealt with where I felt I was getting real value from the software maintenance plan.
And, in case you’re wondering, they didn’t buy me a nice laptop or a 3D mouse to use while writing this. I’m just a satisfied customer :)
-J
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