The Map Is Not The Territory

A blog by Christian Willmes.

My summary of the FOSS4G 2016

| categories: conference, open source, geospatial, osgeo, research | View Comments

Last week I attended the FOSS4G 2016 conference in Bonn. I am still digesting my impressions, because there were a lot of them.
First, the location was really great. The new WCCB around the former german Bundestag parliament building is just beautiful, the technical facilities are brand new. I never sat in more comfortable chairs during a conference before. :-) See the FOSS4G flickr group photos to get an impression of the location (also embedded at the end of this post).

Then, the weather was just amazing, all three conference days with temperature of above 30°C, the venue is directly located at the river front, so you could just step outside and enjoy the weather with a beautiful view on the ships going on the Rhine river.

Besides this perfect boundary conditions for a successful conference, the presentations and talks were of very high quality and quantity too. The programm was very well selcted.

But one of the most remarkable thigs about FOSS4G 2016 is, that the video streaming and recordings of every talk of the conference were just perfect. I think this is because the @c3voc from the famous Chaos Computer Club (CCC) was in charge. Which is just priceless, or in other terms I know of no company you can hire to deliver such a video streaming setup, besides (maybe) a professional bradcasting company. You can find all the recordings from here, enjoy!

Additionally, I had two talks which went pretty well I think.

PaleoMaps talk

My first talk was on the first day of the conference, Wednesday 24th August, 15h at the Fireplace Room. The talk was about a new project we started within our Collaborative Research Centre, titled PaleoMaps: SDI for paleoenvironment GIS data".

Semantic MediaWiki @ OSGeo Wiki talk

My second talk was on the second day of the conference, Thursday 25th August, 12h in the Plenary Office. This talk was about my endeavours to improve the OSGeo wiki for collaboratively storing and handling structured information and data. The talk is titled "SMW @ OSGeo Wiki – How semantics improve the wiki and facilitate a collaborative database for OSGeo".

The conference

The rest of the conference was even more awesome. I was really happy to see the rising amount of talks concerning Linked Data and the Semantic Web. Here is a short list of talks I recommend you to watch the recordings:

  • How Linked Open Data finds the bar near you (Rob van Loon): Abstract | Video
  • Integrating the spatial web with linked open data using GeoDCAT-AP (Paul van Genuchten) : Abstract | Video
  • Spatial data and the Search engines (Paul van Genuchten): Abstract | Video
  • Leaflet.annotate - Semantic markup for geographic web maps in HTML (Malte Reißig): Abstract | Video

The talks on GeoNode and on CKAN were also very interesting to me, because I use those applications as Backend and Middleware for the Research Data Infrastrucutre CRC806-Database, that I develop, build and maintain during my research job at University of Cologne.

  • The Evolution of the GeoNode Community (Jeffrey Johnson): Abstract | Video
  • Implementing Open Geospatial Data Portals with CKAN, pycsw and PublicaMundi: the case (Angelos Tzotsos): Abstract | Video
  • A RESTful API for linking geodata (Francesco Bartoli): Abstract | Video

And one talk, I really want to recommend, is the last Keynote given by Peter Küsterer. The talk was titled: "Sahana as an indispensable tool for disaster management", and it told about the application of the Sahana software to manage the refugee situation in late summer of 2015 in Germany, when >1.000.000 refugees made their way to Germany.

And finally there was the closing ceremony and there were some Awards. The most important award, the Sol Katz Award went to Jeff McKenna, who could not attend the conference, but was able to send thanks and acceptance of the award through a great video message. Jonas Eberle got the best presentation award from the the Academic Track, the award for the best Poster went to Lorraine Barrythat was awarded with 500,- €, and Evan Rouault won the best developer award, that is recognized with 1000,- €. And here you can enjoy the many fotos, that were collected in the FOSS4G flickr pool:

And next year Boston!

The organizing team of the upcoming next FOSS4G 2017, was showing a "wicked awesome" video presenting the next hosting location of the conference series. I am really got fixed to the idea of going to Boston next year. Need to come up with a new idea or project, that I can present there to get my travel fundet by my University. :-)

Have fun!


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Preparations for FOSS4G 2016 in Bonn

| categories: conference, open source, geospatial, osgeo, research | View Comments

FOSS4G Conference

I am very much looking forward to participate in the 2016 FOSS4G conference taking place in Bonn, Germany this year. FOSS4G is one of the conferences I try to participate every year because I really like the spirit of the Open Source Geospatial community that gathers on this international conference series once a year during the dog days. My first FOSS4G was 2010 in Barcelona, then I was in Nottingham 2013 (my blog post about 2013 FOSS4G), 2014 I also attended at FOSS4G in Portland, about which I also blogged. So this year will be my fourth FOSS4G participation! And best is, it will be just around the corner from my home town Cologne, so I can stay at home during the conference and do not need to book travel and a hotel, which is quite weird for participating in an international conference :), but also quite comfortable and indeed cost saving. I will give two talks and will chair one session, on which I introduce some details in the following.

PaleoMaps talk

My first talk will be on the first day of the conference, Wednesday 24th August, 15h at the Fireplace Room. The talk will be about a new project we started within our Collaborative Research Centre, titled PaleoMaps: SDI for paleoenvironment GIS data". Strikingly (to me), the talk has the ID #555 in the conference system :). Here is the abstract of the talk:

Paleoenvironmental studies and according information (data) are abundantly pub-lished and available in the scientific record. However, GIS-based paleoenvironmental information and datasets are comparably rare. Here, we present an OpenScience approach for collecting and creating GIS-based data and maps of paleoenvironments, and publishing them in a web based Spatial Data Infrastructure (SDI),for access by the archaeology and paleoenvironment communities. The Open Science approach to the publication of data, allows to properly cite the published datasets as bibliographic sources in research that builds upon these data sets.This paper has its focus on the implementation and setup of the Free and OpenSource Software for Geospatial (FOSS4G) based SDI, and on the workflow for compiling and publishing the GIS data.

I submitted the talk for the FOSS4G Academic Track, on which I also volunteer as a reviewer and as a Track Editor, about which I will explain further below some more.

Semantic MediaWiki @ OSGeo Wiki talk

My second talk will be on the second day of the conference, Thursday 25th August, 12h in the Plenary Office. This talk is about my endeavours to improve the OSGeo wiki for collaboratively storing and handling structured information and data. The talk is titled "SMW @ OSGeo Wiki – How semantics improve the wiki and facilitate a collaborative database for OSGeo". Coincidentally, the talk has the ID #111, which also bugs me a bit :). The abstract of the talk is given in the following:

Recently, the OSGeo wiki was updated from an ancient version to the current LTS release of MediaWiki. This update broke the functionality of the first OSGeo wiki usermap implementation, dating back to 2008. The map shows the location of OSGeo members on a web map integrated into the wiki. A new version of the usermap [1] was implemented based on Semantic MediaWiki (SMW) [2] to replace the first usermap [3]. This presentation will describe the new features and possibilities that SMW adds to the OSGeo Wiki. After a short introduction to SMW, based on the OSGeo member model, that recently replaced the old usermap, a basic data model and its use in the wiki, as well as major features of SMW are explained. The data model development approach, using mobo [4], applied for implementing the OSGeo Members map will be explained briefly. Additionally, simple examples for bootstrapping smaller semantic models are given too. The presentation concludes with ideas for further applications of SMW in the OSGeo wiki, like the already implemented Advocate and Board lists pages, as well as possible applications, for example a collaboratively maintained OSGeo/FOSS4G service provider directory, or even a collaborative open geospatial data directory are proposed or suggested.

Session Chair

I also volunteer as Session Chair on the third day of the conference, Friday 26th August, Tunnel. The session will host two very interesting talks by well known members of the OSGeo community. The first talk will be given by Pirmin Kalberer on "Using and extending GeoPackages". And the second talk will be given by Sean Gillies on the topic GeoJSON and the IETF.

Academic Track

Additionally, I volunteered for organizing the Academic Track, together with Franz-Josef and Pradeepkumar. I was involved in three paper reviews as a reviewer, and in seven contributions as Track Editor, assigning reviewers and overseeing the review process.


I am sure, this will be a great conference. It will take place at the newly opened World Conference Center Bonn (WCCB), which is build around the former German Bundestag building, including the former Parliaments Plenary Chamber and further facilities of the Bonner Bundestag. It will be a great experience to meet at this historic, and also architecturally interesting place. As said, I am really looking forward to experience this special place, as well to meet all the great people of the Open Source Geospatial community.


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New SemanticMediawiki based OSGeo Member Map

| categories: webdev, semantic web, geospatial, osgeo, semantic mediawiki | View Comments

In this post, I give some background on the new Semantic Mediawik based OSGeo Members map, that replaced the userMap. Starting with the Mediawiki update and introducing Semantic Mediawiki, some words about the history of the userMap and most important an overview of the new implementation and possible additional applications of Semantic Mediawiki in the OSGeo Wiki are given.

The introduction of Semantic Mediawiki into the OSGeo Wiki

Recently, thanks to an effort by OSGeo SAC (namely by Martin Spott), the OSGeo Wiki underlying Mediawiki software was upgraded from an ancient version (I think it was 1.12) to the current 1.25.3. Additionally the Semantic Mediawiki (SMW) extension, including Semantic Maps was installed, to enhance the OSGeo Wiki with its features.

SMW is a Mediawiki extension, that allows to structure wiki content (as data) and provides tools for queriying, export and visualization of this structured data. The Semantic Maps extension adds the capabilitiy to visualize SMW content, containing data of the special type "Geographic Coordinate" on maps. SMW even offers an API that allows to query the structured data stored in the wiki from external applications and export data based on queries. SMW is a mature project running on many large Mediawiki implementations, by well known organizations like NASA, OLPC, The Free Software Directory,, to name just a few.

The OSGeo Wiki userMap

The original OSGeo Wiki userMap, implemented by me in 2008 during an internship at WhereGroup, is now broken because of dependencies of the not anymore supported Mediawiki extension called Simple Forms. The extension implemented a parser hook, that allowed to store the spatial locations of users in a PostGIS database. And parser hooks for including OpenLayers based map into wiki pages, displaying a users Location as well as a map of all were implemented in this first version of the userMap. The now deprecated documentaion is for now still available in the wiki, to get an overview.

SMW based OSGeo Members map

The SMW data model was developed using a tool called mobo. Due to using mobo, it is possible to develop and maintain an SMW data model from a central point in a consistent manner, enhancing maintainability, coordinating possible collaboration and also allowing to grow the Schema to additional applications and scopes over time. Mobo is a command line toolset that helps building Semantic MediaWiki structure in an agile, model driven engineering (MDE) way. The Schema is formulated applying the JSON-Schema specification, in JSON or YAML notation, in a defined folder structure considering file naming conventions. A bit similar to some MVC frameworks for building a web applications domain. The documaentation including a tutorial and examples of the mobo toolkit, can be found here.

The development code files of the mobo model are stored and published in a GitHub repository, for community review and allowing anyone to send pull requests for helping to improve the SMW based capabilities of the OSGeo Wiki.

It was even possible, to save the locations entered through the previous userMap implementation into the mentioned PostGIS table. This was possible by exporting the data from the PosGIS table as CSV, applying some Python foo on the CSV (especially on the geometry wkb notation using Shapely) and importing the data into the wiki as CSV, using the Mediawiki DataTransfer Extension.

Conclusion and Outlook

The application of SMW technology in the OSGeo wiki has, with the introduction of the OSGeo Members model, created a valuable directory that gives a nice overview of the OSGeo community. It is possible to extend the model in the future, to a directory of Charter Members, or OSGeo Advocates. This would yield sortable tables and of course maps of these contacts.

It is even possible to develop models for the Service Providers, to replace the sometimes hard to maintain current Service Provider directory, or for example a model of the Geo4All laboratories to generate directory and an according map. But one of my favorite possible models would be a model for an Open Geo Data directory in the OSGeo wiki.

All these models and the emerging directories would be collaboratively created and maintained by the OSGeo community by just editing the wiki. And not yet to speak of what is possible with the Mediawiki API for querying the structured data and getting the results nicely in JSON format, and by far not yet to speak of enabling the SPARQL-Endpoint which comes with Semantic Mediawiki.

So, the OSGeo Wiki has a bright future If we want. I will do my best for this goal.

Have fun!


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GeoNode installation on two hard disks

| categories: webdev, ubuntu, open source, geospatial, server | View Comments

I had to install GeoNode on a server with a (small) hard disk for the OS (Ubuntu Server) + software, and a second larger hard disk volume for the data. If you install geonode from the package source via apt-get, like me, you need to adapt the data locations to use the large hard disk volume. Otherwise, the data will end up on the small hard disk, where the GeoNode application is installed by default.

Because I had some work to find the best way on configuring the system in such an environment, I thought it would be good to write it into the internet, so that other people searching for solutions can find some.

System setup

As already mentioned the server runs a Ubuntu Server 14.04 LTS OS. GeoNode is installed via package install:

$ sudo add-apt-repository ppa:geonode/testing
$ sudo apt-get update
$ sudo apt-get install geonode

The second larger hard disk is mounted into '/media/data'. The goal is to have at least the most locations, where geonode stores its data on this volume.


According to an equiry on the geonode-users email list (thanks for helpfull answers to Ariel and Matthew), the following locations store the data, and will grow big over time.


In the following, a solution for each of these locations is given.

GeoNode/GeoServer data directory

$ sudo mkdir /media/data/geoserver
$ cd /media/data/geoserver
$ mkdir data
$ cd /usr/share/geoserver
$ sudo ln -s /media/data/geoserver/data/ data
$ sudo chown tomcat7:tomcat7 data -R

Upload directory

$ cd /var/www/geonode
$ sudo mv uploaded /media/data/geonode/
$ sudo ln -s /media/data/geonode/uploaded/ uploaded
$ sudo chown www-data uploaded -R

Tomcat temp (cache) dir

Tomcat will write the cached tiles of GeoNode's GeoWebCache instance, which can get very big, into the tomcat temporary folder. The path of the temporary directory is defined in an environment variable, which is configured in the tomcat init/startup script.

$ cd /etc/init.d
$ sudo nano tomcat7

Find the line


...change it to


Postgresql tablespace

The hardest part of the configuration is to change the file system locations of the postgresql database and its tables. At first we create a directory for the postgresql storage.

$ vmadmin@geonode:/media/data$ mkdir postgresql
$ sudo chown postgres postgresql/ -R
$ cd postgresql/
$ mkdir data
$ sudo chown postgres data/ -R

Next we set the table spaces:

$ sudo su postgres
$ psql
CREATE TABLESPACE exthd LOCATION '/media/data/postgresql/data';

ALTER DATABASE geonode SET default_tablespace = exthd;

\connect geonode

Alter the tables that grow big to new tablespace:

ALTER TABLE documents_document SET TABLESPACE exthd;
ALTER TABLE layers_attribute SET TABLESPACE exthd;
ALTER TABLE layers_layer SET TABLESPACE exthd;
ALTER TABLE layers_layer_styles SET TABLESPACE exthd;
ALTER TABLE layers_layerfile SET TABLESPACE exthd;
ALTER TABLE layers_style SET TABLESPACE exthd;
ALTER TABLE layers_uploadsession SET TABLESPACE exthd;
ALTER TABLE maps_maplayer SET TABLESPACE exthd;
ALTER TABLE maps_mapsnapshot SET TABLESPACE exthd;
ALTER TABLE services_service SET TABLESPACE exthd;
ALTER TABLE services_servicelayer SET TABLESPACE exthd;
ALTER TABLE services_serviceprofilerole SET TABLESPACE exthd;
ALTER TABLE services_webserviceharvestlayersjob SET TABLESPACE exthd;
ALTER TABLE services_webserviceregistrationjob SET TABLESPACE exthd;
ALTER TABLE upload_upload SET TABLESPACE exthd;
ALTER TABLE upload_uploadfile SET TABLESPACE exthd;

The tables are pure assumption, its possible to alter the tablespace of more tables later on, if further tables proof to store much data. Thats it, so far... until now everything runs as expected on the system, and the right locations store the data. I'll keep you posted if I need to adapt anything on the system.

Have fun!


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FOSS4G 2014 Portland recap

| categories: conference, geospatial, open source | View Comments

I was lucky to get a talk in at this years FOSS4G academic track, which allowed me to travel to Portland, Oregon. The talk was about a project in which we applyed Köppen-Geiger climate classifications to paleo climate model simulations, using GRASS GIS. The talks were recorded and shared on vimeo, so enjoy! :).

Köppen-Geiger classifications of paleoclimate model simulations — Christian Willmes, University of Cologne from FOSS4G on Vimeo.

The slides of my talk are accessible from the foss4g 2014 slides collection on github and from the CRC 806 database.

The FOSS4G program itself was huge. Eight (8) parallel tracks plus an extra track for Invited talks and Keynotes. So it was not at all possible to attend all the talks that you had an interest in. You can find the recordings of mostly all talks on vimeo and they are also linked directly from the schedule. This great organization and technical skill which deliverd almost all the recordings in that short time to the crowd is by itself a great acheivment of this years FOSS4G hosts, the OSGeo PDX team.

I was wondering about the organization of the academic track in the program schedule, because there was none, at least to my knowledge. So I could not see which presentations in the programm were from the academic track, I could only guess based on the titles and abstracts of the talks. This was sad, because I would have liked to attend most acedemic talks to maybe network with other academics using and developing FOSS4G.

I also have a subtle feeling, that the academic track has a not so well standing for many of the core FOSS4G participants. I think this is a pity, because those pesky academics ;-) are teaching the FOSS4G tools to their students and use them for - and promote them in - their academic works. This creates new users and maybe even developers for the projects and the community can only win from this. Thus, I would strongly recommend to better promote the academic track on future FOSS4G conferences, to increase visibility and thus also the quality of the academic track. To have the oportunity of publishing the submissions in the Transactions in GIS Journal is a big advantage and makes the submissions for academics to FOSS4G attractive. And those who are bored by academic talks do not have to attend them. There is no downside of having a prominent academic track on FOSS4G conferences, as far as I can see.

On Saturday after the conference I attended the code sprint, and had the opportunity to work a bit on the planned OSGeo Journal' OJS system update and on the update of the Wiki usermap, that we/I try to migrate to a Semantic Mediawiki based implementation (which seems to be a bigger story, on which I might have an additional post in the near future). Anyway, I enjoyed to sat down there, breathe the air of an OSGeo code sprint and gave the OJS update a try, but I did not prepared anything beforehand and I ran into some MySQL level problems durig a test run of the update on my local environment, which I could not solve on the code sprint.

In recap, I had a very good time in Portland and at FOSS4G, during the conference as well as the two days before and after the conference. Before the conference, on my first day in Portland I went to the Portland Timbers vs. San Jose Earthquake match at providence park joining the FOSS4G Timbers field trip. It was a quite entertaining match, with a final score of 3:3 (6 goals!). On this way thanks to the organizers of this field trip again! After the conference I had an awesome roadtrip from Portland, along Eugene, Crater Lake, the Oregon and north California coast, the Redwood trees, Napa Valley to the Bay Area and San Fransisco, from where my flight back home was heading.

Have fun!


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