Sessions at Open Source Bridge 2011 about GIS on Wednesday 22nd June

So, you think you’ve got a great idea for a map, but little to no experience in map-making? Have you been making maps, but want to increase your understanding of what’s going on “under the hood”? Do you think maps are nothing but a bunch of latitude and longitude points? Then this session is for you.

We’ll introduce you to the concepts you need to know to really understand how maps work: technically, visually, and even socially. We’ll cover how your data gets from the real world to your screen, why every map is a lie, how to think about your data, and how to make your data pretty and understandable. Then we’ll talk about where to find data, and just as importantly, how to understand your data, and how to make sure the lie your map is telling is the one you mean it to. Finally, we’ll talk briefly about what open source tools are out there to help you manipulate and display your data.

If you're doing interesting things with geospatial data you will need to take multiple sources in various formats and with bizarre non-standard projections. This session is focused on practical recipes for dealing with esri shapefiles as provided by local governments, raster data from sensor surveys, and other stranger formats that are out there.

Items that will be covered include:

1. How to read a projection that doesn't match anything in spatial_ref_systems

2. How to register geotiff and dem datasets onto polygons (so you can do things like calculate the vegetation groundcover percentage on taxlots).

3. Exporting geodata to other file formats for use in other programs.

This is an intensely practical session that is designed to help fill in some of the knowledge gaps that those starting out working on geographic data have. Some basic knowledge of postgresql and the bash shell is assumed.

Example data sets will be drawn from the US Census, the City of Albany (Oregon), state of Oregon vegetation surveys and other sources.