The new Geographic Information Systems Stack Exchange site is now open to the public!
It’s brand new, and has the potential to be an extremely valuable resource for GIS professionals, academics, enthusiasts, and just about anyone else looking for answers to GIS related questions.
Check it out here: http://gis.stackexchange.com
Carson
For part of a traffic simulation project I am currently working on we need country-wide road network data for Ireland. In the past, getting decent road network data for an area this large was quite a task (not to mention expensive and time consuming), however, with OpenStreetMap we have access to this type of data instantly, and for free! In order to download full country coverage all at once, all I had to do was turn to this extremely useful site, which provides links for daily excerpts of OpenStreetMap data for any country in Europe plus several non-country regions such as the Alps region, as well as select countries outside of Europe. It currently also features special coverage of Haiti.
Now that I have the OSM data downloaded, it should be relatively easy to import it into my PostGIS database using pgRouting and the osm2pgrouting import tool. More to come on this topic once I get things working nicely…
Carson
Several colleagues of mine have asked whether it is possible to visualise the results of a SELECT statement on a PostGIS database that returns spatial data in QGIS. In other words, can we map the results of something like SELECT id, st_union(the_geom) FROM spatial_table GROUP BY id;. My usual answer to this in the past has been “not yet…”, but now thanks to Giuseppe Sucameli and Jürgen E. Fischer, the answer is a resounding “yes!”. A recent patch to QGIS trunk now makes custom Postgres queries possible via the postgres data provider.
Last night I had an uncontrollable urge to make geopoprocessing in QGIS better, faster and more fun! I had come across a couple of posts (here, here) on the idea of a cascaded union operation, and since it has recently been added to GEOS (which QGIS uses for its geometry operations), I thought I’d give a much needed boost to the fTools union tool and related functions.
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Last week I attended the 2009 QGIS Developers Meeting in Vienna, Austria. We all had a really good time, met many new people, and actually got a lot done in the process. There have been updates about the meeting (hackfest) on the QGIS blog, and Tim Sutton has written a few words about our progress as well. I’m not going to repeat what others have said, but I would like to give a quick update on the work that I was doing at the meeting, and show off the new geoprocessing features now available to all QGIS developers (Python and C++).
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My latest article, “Identification of snow cover regimes through spatial and temporal clustering of satellite microwave brightness temperatures”, has recently been published on-line , with the journal Remote Sensing of Environment. For now,
UPDATE:
The article can be cited as:
Farmer, C. J. Q., Nelson, T. A., Wulder, M.A. and Derksen, C. (2010). Identification of snow cover regimes through spatial and temporal clustering of satellite microwave brightness temperatures, Remote Sensing of Environment, 114 (1): 199-210.
If you would like a copy, but do not have access to the article, please email me and I can forward you a PDF version.
C
Announcing an opportunity to learn about the leading edge free and open-source technologies for desktop and web-based mapping and data analysis. This is a two day Masterclass focusing on introducing participants to the wonderful world of open source geospatial software. Check out the announcement from the Postgraduate Statistics Centre at Lancaster University.
C
Check out the Journal of Spatial Information Science, a new, peer-reviewed, open-access journal with a range of well established geospatial academics on the editorial board.
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Two quicks notes to share:
Firstly, please check out this excellent introduction to GIS by Tim Sutton, Otto Dassau, and Marcelle Sutton in partnership with the Chief Directorate for Spatial Planning & Information, Department of Land Affairs, Eastern Cape, South Africa, and the Spatial Information Management Unit, Office of the Premier, Eastern Cape, South Africa. They use QGIS to present some basic GIS concepts and skills, and I particularly like their section on Coordinate Reference Systems.
Secondly, don’t forget to checkout the FOSS4G 2009 Free and open source software for geospatial conference in Sydney in October. There will be loads of excellent presentations and exhibitors, and the atmosphere is always very cool. I will be presenting some software that I’ve been developing for a while now, and will hopefully get a chance to represent QGIS there as well!
C
OpenStreetMap (OSM) is a project designed to create and provide free spatial data (street maps) to anyone and everyone who wants them. It is based on an open-source philosophy, and combines wiki-like user generated data, with free access, allowing users to create, edit, download, and use OSM data to their hearts content. According to the OSM website, “the project was started because most maps you think of as free actually have legal or technical restrictions on their use, holding back people from using them in creative, productive or unexpected ways.” There are now tones of websites and open-source software projects that incorporate OSM data, and the growing popularity of the site means that the data is only going to get better (more accurate) and bigger (more data).