Open Source GIS Wrap-up
I’ve been on an open source GIS tear this month, so in this post I’ll wrap up some odds and ends:
- There is a project called Sextante, which is essentially an open source ArcToolbox for gvSIG. It adds a lot of geoprocessing and analysis functions and is pretty easy to install. There are 200 + tools in the box, but for some reason not all of them are active. I’m not sure why this is the case, but haven’t poked around much to find out.
- There are also a number of extra plugins for QGIS that are available through the QGIS wiki under PluginRepository; they include plugins that add more symbolization and that make table joins possible. Haven’t had a chance to try this yet either, but it sounds like these extras could make QGIS a lot more viable as a thematic mapping option.
- I found out about the QGIS plugins from this article, which offers a good overview of QGIS. The article also discusses one of the other shortcomings of open source GIS – the lack of a support for a simple, desktop geodatabase similar to the Microsoft Access personal geodatabases. PostGIS is certainly powerful and there has been a lot written about it, but a server based geodatabase is not always the best solution, particularly for small, stand-alone projects. There is a cool project called Spatiallite, where someone has created geographically enabled SQLite databases (which are small, stand alone dbs). You can export shapefiles to them, or simply view and edit the attributes in a shapefile via a virtual connection. Based on what I’ve looked at thus far, you can access SQlite databases directly in GRASS and when using GRASS datasets via QGIS, but I haven’t been able to connect to a SQlite db with the other software I’ve looked at – it’s just not supported yet.
- In researching open source GIS, I’ve looked at a book specifically on GRASS, Open Source GIS: A Grass Approach, as well as two books on web mapping (GIS for Web Developers: Adding ‘Where’ to Your Web Applications and Web Mapping Illustrated: Using Open Source GIS Toolkits)which cover GDAL and OGR, QGIS, GIS servers, PostGIS and PostgreSQL, and a few other tools. There is a book that’s recently been published that focusses specifically on Open Source Desktop GIS – Desktop GIS: Mapping the Planet with Open Source Tools. I pre-ordered a copy on Amazon that was supposed to ship in Mid September, but is now being delayed until late October. Based on the table of contents it looks pretty thorough and covers many of the choices I listed in my previous post, and I’m looking forward to its arrival.