The collaborative mode of operation of the ANR ALPAGE project revolved around several plenary meetings a year, alternating between La Rochelle and Paris. The aim of these meetings was to review the progress of the collective work. This progress is visible in the detailed minutes of these sessions that were attended each time by around 15 people including historians, geomaticians and computer scientists.
The georeferencing and vectorising of the most ancient available Parisian cadastral layers lies at the heart of the ALPAGE project. From this spatial reference (base maps) historical layers, mainly comprising the topography and the medieval and modern administrative boundaries, have been created.
The source plans correspond to the 910 Atlas Vasserot urban block plans (1810-1836): these plans contain the finest representation of the 12 ancient ‘arrondissements’ (administrative districts) in pre-Haussmann Paris and indicate not only the road networks, but also the plots and the buildings (plan of cross-sectional view 1m above ground).
After completion of the georeferencing phase of the 910 Vasserot urban block plans and during the vectorisation phase of these images, historians – mainly medievalist historians – created several historical layers based on their own thematic research. Those historians trained and advised by the project’s geomaticians created their own geo-historical data in a Shapefile format. This work has taken into account the experiments already carried out or planned, in particular at the Ministère de la Culture (CNAU: Centre National d’Archéologie Urbaine), by reusing notably the simple but robust conceptual data model of functional entities using time as an attribute.