Wednesday, February 09, 2011

From Shapefiles to GeoSynchronization – ‘Pretty Damn Cool’

In our visits with folks over the last few months we’re finding growing interest in geospatial collaboration and interoperability. They see value in new technologies like GeoSynchronization that allow them to get updates from many sources, validate them if required, and syndicate them to the people and systems that need them through real-time feeds. But local, county, state, provincial and federal organizations still have a job to do. They have to get current data updates out, meet deadlines and work with systems they have today. For geospatial data production this often means using ESRI Shapefiles, a popular geospatial data format for GIS software.

So how do we bridge the gap between a future environment of online services like GeoSynchronization and current Shapefile-based production methods – and do it so organizations get the benefits without disrupting current processes? The answer lies in transforming Shapefiles into GeoSynchronizable transactions that can be used by any web service implementing open geospatial (OGC) standards. Here’s an example from our recent NSDI grant work with the State of Arkansas in the US.

Currently, Arkansas state GIS receives a drop of Shapefiles-based road data from over 70 counties about every month. These files are ingested into the state-level view, including all provided data and updates, and state personnel use their GIS systems to assess what's changed. To help speed up this process we’ve extended our CarbonCloud Sync services and clients to accommodate current workflows and data sources, while maintaining GeoSynchronization capabilities and benefits. We do this by -
  • Reading the county Road Centerline Shapefiles into a new application called the GSS Change Validator,
  • Comparing them against existing state data on an ArcGIS Web Feature Service (with GML),
  • Automatically determining what’s changed,
  • Generating change-based transactions for the county roads data. In other words, is it an Insert/Update/Delete? (the example above shows a Road as an 'Insert' transaction),
  • Then sending the updates to the people and systems that need them through CarbonCloud Sync (including federal-level web services if needed).
This approach meets the needs of state data production organizations and the GeoSynchronization vision of the CAP grant - it also has the benefit of providing a very quick assessment of what’s new in each county.

When we showed the approach to a community group recently we received responses like “this will save us lots of time and money” and “pretty damn cool”. In the next few weeks we’ll break down more details of how it works, how other sources can be converted into geosynchronizable transactions and notifications, and how the approach can help other communities move to syndicated networks of real-time geospatial updates.

- Jeff