Open Source Technology

Site Archive
You are viewing a static copy of the 2009 Sunriver Conference website archived on December 11, 2013. To view current Northwest GIS User Group events and news, visit nwgis.org.
Open source software is software where the source code is made available under a license that allows the modification, and re-distribution of the software at will. The precise definition of open source software used by the foundation is the OSI's Open Source Definition, and a variety of additional information can be found at the Open Source Initiative web site.

Building a low budget Web GIS for the Obama Campaign using Mapserver, PostGIS and Openlayers

The talk describes a web GIS application based on open source geospatial software components that was built for the Obama Campaign during the 2008 US presidential election. The goal of the application was to support the work of campaign field organizers in battleground states for voter targeting and prioritization purposes. Technically the application was hosted on an Amazon EC2 server running an Ubuntu (Linux) operating system, Apache 2 HTTP Server, PHP server side scripting and included three main building blocks of the web GIS: a spatial database (PostGIS), a map rendering engine (MapServer), and a mapping framework which supplies the map viewer (OpenLayers). The initial application was set-up for the state of Indiana as a template and was used as a model to build similar applications for other battleground states to follow. The idea was that all battleground states have their dedicated website and data sources, but share the server applications and GIS components. Data relevant to the Campaign such as voter registration percentages, voter persuasion rates, and vote activities of prior elections were mapped on voting district (precincts) level. In addition information about individual voters and their likely candidate of choice, along with a variety of base layers were published as Web Map Services (WMS) via MapServer. Many of the relevant election data in the PostGIS databases were then updated by the campaign on a daily basis. Spatial data from WMS were then draped over background layers such as Yahoo or Google base maps in the OpenLayers map viewer. The template-oriented approach worked well for the campaign and later was rolled out to about a dozen battleground states. The project illustrates how powerful interoperable OS GIS components can be, even with minimal customization and on a low budget: http://www.geoconnexion.com/uploads/open_sources_18_intv8i3.pdf

Presenter(s): 
Karsten Vennemann
Biography: 

Karsten Vennemann is a GIS professional with a background in Geography and Soil Science. His work mostly focuses on GIS in the context of natural resources, sustainable development and social justice. In 2007 he started his own company, Terra GIS (http://terragis.net), based in Seattle, Washington, USA.

4.21739
Your rating: None Average: 4.2 (23 votes)

Implementing Web GIS Solutions using Open Source Geospatial Software

The talk gives an overview on building web GIS solutions using open source geospatial software components. A selection of the most advanced and popular open source components and their roles and functionality in an application framework are described. A complete stack for building web GIS solutions may include a client-server application framework, a web mapping engine supporting cartographic rendering functionality and basic GIS capabilities, data storage solutions such as spatial databases, and additional tools extending or enhancing the GIS capabilities of the mapping engine. The concept of an interoperable software solution is illustrated using a variety of examples. Web GIS application frameworks are either complete client-server solutions such as MapFish and Mapbender or Web GIS clients such as Open Layers and Ka-Map. Internet mapping engines such as MapServer and GeoServer render images, provide basic GIS functionality and/or provide the functionality for serving Web mapping services (WMS) and Web feature Services (WFS). Using cached and tiled data in a web GIS application can substantially speed up its response time. TileCache is a server and caching solution that can be used for the creation of cached data from WMS. Feature Server provides data conversion of simple features from a variety of input formats into target formats such as JSON, GML and KML and can be used to integrate the framework with additional applications. Spatial databases include solutions such as PostGIS and MySQL. PostGIS itself provides comprehensive GIS capabilities that can greatly extend the mapping engine’s capabilities and simplify execution of geo-processing tasks using spatial SQL. Additional tools can be integrated with the framework to provide specific GIS capabilities.

Presenter(s): 
Karsten Vennemann
Biography: 

Karsten Vennemann is a GIS professional with a background in Geography and Soil Science. His work mostly focuses on GIS in the context of natural resources, sustainable development and social justice. In 2007 he started his own company, Terra GIS (http://terragis.net), based in Seattle, Washington, USA.

4.16
Your rating: None Average: 4.2 (25 votes)