The Geometries of Vimy Ridge, 100 years ago


The Battle of Vimy Ridge began 100 years ago on April 9th through 12th, 1917. It holds importance in the Canadian consciousness in that this was the first time that the Canadian Corps fought as a single unit on the Western Front with the 1st, 2nd, 3rd and 4th Division deployed side-by-side1. With a lot of patient geo-referencing work and a joint efforts between Muninn, the Canadian Expeditionary Force Study Group and Wikiwar, a number of the units locations, place names and trenches have been extracted. The simplest way at the moment to visualize the locations is through the Open Historical Map which is an OSM-like website that records historical mapping data and can export the raw geometries for further use. 

At the time of the Battle of Vimy Ridge, the Headquarters of the Canadian Corps were located near Camblain-l'Abbé  (Painted by David B. Milne in 1917). The 1st Canadian Division Headquarters was located in Écoivres near the banks of the La Scarpe river. It's troops were the southernmost deployed with the 17th Corps at their right and the 2nd Canadian Division at their left. The 2nd Canadian Division Headquarters was in a farmer's field near route D58 (There is a google street view pictures of the houses and farms at that current location). The 3rd Canadian Division was next to the left and the 3rd Canadian Division Headquarters was located in Villers-au-Bois. The 4th Division was the northernmost with its flank against the 1st Corps and the 4th Division Headquarters located in a farmer's field near route D65.

How accurate is this information?

A survey section during the war would be expected to triangulate a feature within 20 yards while out in the field. In actuality areas of high activity were well surveyed and the accuracy of a trench map is often within 5 yards for important features. Since we used hand tracing to extract the trenches some inaccuracy is to be expected. One can do much better by creating a line finding algorithm that traces the trench based on colour separation and that will be the topic of future work. The figure to the right is an overlay of the German trenches extracted from a trench map over the Open Street Map's rendering of the current preserve trenches at the Vimy Ridge Memorial. The alignment is not perfect, but sufficient for way-finding purposes.

The location of the Headquarters and the area of operations of the different Divisions, Brigades and Battalions are derived from an aggregate map that was reprojected based on landmarks contained within the current landscape and those within other georeferenced trench maps of the period. The original map was not to scale and large (a 100 meters of so) errors in location can be expected. Of course, features such as a Battalion's area of operations are very large and even a Brigade headquarters involves multiple tents and/or buildings. The map locations on the original source map were simple icons which created their own spatial inaccuracies and one should expect large errors in the actual location. Whenever possible, you should use these features as general areas and not consider their centroid as the ground truth.

This represents the best information currently available and the geometries will improve over time as more information is unearthed. All of these geometries are available from the Open Historical Map's export function which works with all of the tools that were designed for the Open Street Map. 

Where did you get this information?

The trenches and trench name information were extracted from maps M_81_000287 and M_89_000382 in the Imperial War Museum's archive.  The parameters for the reprojection are described in [1], [2] and this ontology document. Tracing was done manually and exported to both shape files and RDF before being imported to the Open Historical Map. 

The location of the headquarters and units during the onset of the battle are derived from the aggregate "map 7" from the Official History of the Canadian Army in the First World War: Canadian Expeditionary Force, 1914-1919 ([3]). The original book was scrubbed for image quality and reprocessed by the good folks at the Canadian Expeditionary Force Study Group before its map was reprojected and bounding areas created before being exported to the Open Historical map.

1. The 5th Canadian Division was not fully formed at the time and it's units were absorbed by the other Divisions.


Posted By warren read more

Time to say goodbye to an old friend


When the Muninn Project started several years ago, it was a wild idea that started at the paper napkin stage and that slowly evolved into one of the more complex projects in the Linked Data Cloud today. Along the way, Muninn's mascot Le Corbeau was chosen, as designed by "Steve" on a free CC clipart site which has since disappeared along with any lineage and provenance data. While at the time that decision seemed sound, it isn't great not knowing the status of an abandoned clip art and to this end, we ended up asking a designer to create a version of the Corbeau specially for Muninn. The designer is Erin Windrim from Toronto who also released her work under the Creative Common license. She's currently working on the next batch of stickers that you you'll be able to get at a future conference!

Posted By warren read more
Posted By warren read more

One URI for the Great War


The Great War occurred again during a session at the #lodlam Summit in Sydney that was held in the Mitchell Library and hosted by the State Library of New South Wales.

One of our conversation turned on the use of a global subject identifier for the Great War since most systems still represent it as a series of strings: "The Great War, Great War (1914-1918), World War One, WW1, etc... Furthermore, different nations entered the conflict at different times (The United States entered the war in 1917) which implies that the event is seen as matching or not different views of the event, e.g.: Great War (1914-1918) versus Great War (1917-1918).

To get around this we created a global URI for any and all aspects of the Great War:

The term contains labels in several languages that we will keep adding on to and the human-readable term definition is "Any data related to the Great War" which should be wide enough for all usage. You don't need to agree with this definition: through the use of OWL, OWL2 and SKOS vocabularies you can further refine your own collection subject heading by linking to the above URL. The linking aspect is what will enable more people to find you collection and its holdings.

So, if you have a collection or items that are about anything related to the Great War, do:

  • Use the term directly as a subject heading, OR:
  • owl:sameAs's to it with your own subject heading, OR:
  • owl:differentFrom to it if you disagree with how we are going about this, OR:
  • skos:exactMatch to it if you live in the SKOS world and agree with the term, OR:
  • skos:closeMatch to it if you live in the SKOS world and the term is close to what you think the Great War should be, OR:
  • skos:broadMatch to it if you live in the SKOS world and the term is too broad for your needs, OR:
  • rdf:subClass to it if you live in the OWL/RDF world and the term is too broad for your needs, BUT:

Do link to the term if you are working on the Great War. Linking is the only way we are going to get Linked Open Data working for everybody.


Posted By warren read more

The Business Value of Linked Open Data


Note: The following is a synopsis of comments I made to the Publishing and Managing Linked Open Data in Cultural Heritage Institutions session at Museums on the Web 2015. I'm posting them after a follow up conversation with Cristina Pattuelli of the Linked Jazz Project.

What is the business value of Linked Open Data? What is the business case that drives you to support / invest / develop into yet-another-platform and what will it do for your business/library/museum/archive/store-front? Anecdotal, academic and one-off examples aside, why should you care?

A quick answer to these questions In three parts: because a) it promotes and facilitates citation (eg: Marketing), b) creates cost externalization opportunities  (eg: Get other people to do your work) and c) it leverages the idiosyncrasies of your business (eg: Your unique selling proposition).

Posted By warren read more

Muninn LODLAM Challenge


The Muninn Project is submitting the following video to the LODLAM Challenge, consider voting for it on the LODLAM Challenge Web Page . 

Posted By warren read more

Print your own Battlefield


The Muninn Project aims to programmatically recreate scenes of historical events using Linked Open Data - and with the ever-increasing availability of high-quality 3D printers, we are motivated to 3D-print these scenes. In this particular post, we will talk about how to 3D-print a battlefield: the trenches of Vimy Ridge. We believe that 3D-printed models of battlefields, such as the trenches of Vimy Ridge, could be quite useful to archeologists & other individuals studying past historical events, namely the Battle of Vimy Ridge. We will discuss how to retrieve 90m-resolution elevation data inside a bounding box from the Shuttle Radar Topography Mission (SRTM), how to scale & project it with the Geospatial Data Abstraction Library (GDAL) and also how to convert it to an STL file that can be 3D-printed; we will also discuss how to retrieve lists of trench coordinates from the Muninn Project's SPARQL server, and how to extrude trenches on our model of Vimy Ridge before 3D-printing it. Lastly, we will discuss issues regarding the size & resolution of our model of Vimy Ridge and suggest how we might improve the quality of our model in the future. Thanks to Lawrence Willett for letting us use his 3D printer.

Posted By m4farrel read more

Reusing LOD Vocabularies: It's not all it's cracked up to be.


"Re-use data, re-use vocabularies", this has been the battle cry for Linked Open Data and Semantic Web enthusiasts since day one. Formally, the W3C Government Linked Data Working Group has published a Working Group Note on the matter where they state that "Standardized vocabularies should be reused as much as possible to facilitate inclusion and expansion of the Web of data". What seems to be a reasonable point of vue has been pushed a little bit too strongly of late.

Posted By warren read more

Transcribed CEF Medical Files as Linked Open Data on the Canada Open Data Portal


Word cloud from the transcribed contents of the medical case sheets

One of the collections that Library and Archives Canada has been digitizing and putting for access online has been the personnel records of the soldiers of the Canadian Expeditionary Force sent to Europe during the Great War. A typical personnel file is a folder containing about 100 pages of documentation about the soldier himself and sometimes includes his medical records in the form of temperature charts, dental records and medical case sheets. In this project it was decided to focus on the contents of the "Medical Case Sheet" that is a lined form used by hospital staff to record information about their patient.

Posted By warren read more

Retrieving Historical Photos of Film Stars using DBpedia


This is a follow-up to the previous blog post on retrieving historical art from the Rijksmuseum. Like historical art, film star photos inform us about politics and human culture at particular times throughout history - but there are so many film star photos that it becomes difficult to devote sufficient attention to each individual photo. We can use DBpedia to retrieve historical photos of film stars and display them in our statistically generated scenes of historical events. We'll display both film star photos and historical art that best fit the contexts of our statistically generated scenes - and use the context of the scenes that they are placed in to interpret them for their historical significance.

Posted By m4farrel read more


Subscribe to The Muninn Project RSS