This time I will be talking about “Open Source Tools for Spatial Analysis and Geoprocessing on the Desktop“. A general introduction and overview about the tools covered in this workshop will be followed by examples illustrating the use of desktop utilities based on the OGR/GDAL2 libraries, PostGIS (“the” open source spatial database) and gvSIG (a desktop GIS) for spatial analysis and geoprocessing. During the workshop participants can use a live DVD with their own laptop to go along with some of the exercises.

The workshop consists of the following three parts (with 15 minutes breaks in between the 3 sessions):

1. Introduction to Free and Open Source GIS Tools on the Desktop
   Participants will get a short introduction to the world of Free and Open Source Geospatial (FOSS4G) and about the specific OS tools used in this workshop and their capabilities: OGR/GDAL, gvSIG and PostGIS. (60 minutes, presentation style)
2. Examples for Spatial Analysis and Geoprocessing using OGR/GDAL, gvSIG and PostGIS
   Examples of how to use OS tools for Spatial Analysis and Geoprocessing. This session covers 3 parts:
   a. Using the Open GIS Simple Features Reference Implementation and Geospatial Data Abstraction Libraries (OGR/GDAL) and other desktop utilities to manipulate vector and raster data sources.
   b. Using the desktop GIS gvSIG and the Sextante extension for your geoprocessing and spatial analysis needs. gvSIG is a powerful desktop GIS and together with the Sextante extension can be used for comprehensive GIS tasks and Image analysis. This combined gvSIG/Sextante system includes more than 220 geospatial analysis functions (for raster and vector data), some of which will be explored in this session.
   c. Using the open source spatial database PostGIS (based on PostgreSQL) for geoprocessing is another highly effective and powerful way to do spatial analysis. Because PostGIS exposes it’s functionality directly to SQL many tasks can be performed by simply writing spatial SQL queries or functions.
   (90 minutes, presentation style and a lot of live examples, participants can follow some demos
   ‘hands-on” using the live CD)

3. Using OS tools for your everyday Spatial Analysis and Geoprocessing Tasks
   To illustrate the capabilities of the tools and their use in real world situations and for your day to day geospatial processing tasks. In short this session covers more examples of how to put our OS tools to work. (60 minutes, presentation style and a lot of live examples, participants can follow some demos
   ‘hands-on” using the live CD)

The official workshop webpage can be found here

Some weeks ago I had the task to get a schema of the US census summary files into PostgreSQL to subsequently being able to load the entire US data for those summary files (SF1 and SF3).

After some searching on the web I found schemas for those summary files in Access mdb format (SF1 template and SF3 template). Many of the tables in the summary files have well over 100 columns (see screen shoot in pgAdmin on the left hand side) and there are more than 200 tables for both summary files combined. So that was definitely not a quick “punch-the-table-schema-in-quickly” job to recreate the tables in PostgreSQL. Again searching on the web I stumbled about this post mentioning the excellent mdbtools. Great - just the right tool found in time. Since the server where the work is supposed to happen runs Ubuntu there was even no need to compile the mdb tools program at all.

After running the sql files I had the schemas loaded in almost no time. On this blog there is even a python program using the mdb tools that allows you to directly extract data from mdb files into csv format - sweet.

Have fun unlocking your data !

Some months ago I was lucky enough to secure a couple of small contracts with the Obama for America Campaign to support their general effort and the work of the field organizers by implementing some web mapping capabilities. After some phone discussions with the Obama Technology team it actually was not hard to convince them to go the open source route and setup a server on Amazon EC2. We took an existing Ubuntu-based server image that included most of the Open Source GIS stack already (many thanks to Josh Livni of Umbrella Consulting who created the public image and who also has instructions on his website on how to set this up quickly: http://os.umbrellaconsulting.com/wiki/AmazonEC2).

The EC2 server was running on an Ubuntu operating system, Apache 2 HTTP Server, PHP server side scripting, PostGIS spatial database, OpenLayers as a map viewer, and UMN MapServer in CGI mode as the map rendering engine. The goal was to support the field work of organizers in up to twenty battleground states, and to scale the application vertically in case that was needed. We initially setup an application for the state of Indiana as a template that could be used as a model to build similar applications for other battleground states to follow. A couple of million geocoded voter records were uploaded into PostGIS and could be accessed in the OpenLayers based viewer as a MapServer point layer on top of a selection of commercial background layers (such as Goggle satellite images, street or terrain layers, or Yahoo street layers). A variety of base layers, such as county and precinct boundaries, along with daily changing information on voter related ratings (as a transparent polygon layer on precinct level) were made available and could be draped over the background layers. Performance of this “all on one server setup” was reasonable, given that of approximately two million (color coded) voter points in the PostGIS database, only a portion would be displayed on high zoom levels. This approach worked really well for the campaign and later was rolled out for about a dozen battleground states.

Another small tidbit of work involved setting up a tool for assigning a list of voters to an specific organizer to contact for campaigning purposes. The setup included a tool for digitizing polygons in the OpenLayers viewer (which is standard functionality) and customization of the tool in such a way that it allows the selection of all voters located within the digitized area via a simple spatial SQL query using PostGIS to perform a point-in-polygon query. Subsequently an update of a column in the database with the name of an organizer would be triggered by the tool and a second tool would enable the export of the respective voter lists from the database via PHP to text files for download.

From a technology standpoint the whole project was a pretty simple use of interoperable and readily available OS geospatial software components: it also illustrates how powerful those combined components can be, even with minimal customization and on a low budget - as long as the correct data is available and there is an energetic field organizer team behind it. Last but not least I wanted to mention that if this work contributed its small bit to winning this crucial election I am really more than happy.

Congratulations to the Obama Campaign! I can’t wait to experience some mindful changes to become reality…

The main topics of the class/hands on workshop are as follows:

The overall focus of the class will be along the lines of Mapserver, PostGIS and OpenLayers. However, the whole spectrum of Web GIS components will be introduced as an overview. To get an idea about the most advanced and popular web GIS components download the presentation Implementing Web GIS Solutions using open source software. During the class there will be a lot of opportunity for discussions and question and answer sessions.

The class will be presented by Karsten Vennemann who has several years of experience with FOSS4G software and has lead numerous workshops in GIS throughout his 12 year career in GIS.

Dates: December 3rd through Friday December 5th, 2008 (9:00 am - 5:00 pm,  one hour lunch break)
Please inquire about other dates if you are interested in the class

Location: Capitol Hill Neighborhood, Seattle WA, USA
Exact class location will be send to registered participants

Costs: US $900/per person when bringing your own windows laptop (1050$/person with rental Laptop)
Payable at time of registration

Target Audience/Prerequisites: GIS Specialists/Analysts/Programmers (at least intermediate level - as no GIS basics will be covered) . This is an introductory class about web mapping with FOSS4G and not really a  programming class (some scripting will be used in Javas Script and PHP though) . Some knowledge about the following is advantageous (but not required):  JavaScript, HTML, PHP, webpage design, (spatial) databases, web servers

Participants: Maximum class size of 10

Registration: Please contact us via email or call 206 905 1711 if you like to register or have additional questions

“Our friends at CommEn Space recently released a prototype version of an online list enhancement tool that can provide the legislative district (LD) number and county name for the addresses of your membership and prospect lists.

Washington Conservation Voters Education Fund (WCV Ed Fund) and their Priorities for a Healthy Washington coalition partners use the tool to automatically add the LD number and county name to lists of up to 1000 addresses at once… “

more - read the original article on ONEList

claro que si.