The Orbis Romanus Atlas is neither an interactive atlas nor an atlas published in print only. It is intended to be a definitive database of ancient geography containing as much information as possible on any single place in the Roman Empire. The maps drawn from this database can then be restricted to a certain period in time or to particular military or civil functions of places. As such the atlas is in a state of continuous growth and differs e.g. from the Classical Atlas Project.
Eventually the atlas will cover all of Europe, Africa and Asia between longitudes West 10 and East 60 and latitudes North 60 and North 20, though in principal there need be no limitation on the spatial coverage.
There is no fixed scale defined for the map since the scale might change with the depth of information available for a particular region. The precision of location is currently given by 1 arc minute in latitude and longitude corresponding to ca. 1.5km at 50 deg North. The resolution of the physical landscape is 30 arc seconds. For purposes of printing the scale is usually optimized either to A4 or A3 paper size. For a typical region of 3 deg longitude and 2 deg latitude this means a scale of 1:1250000 for A4 and 1:800000 for A3 landscape. The projection of choice is a conical Lambert projection which allows multiple sheets to be glued together.
For places where times of foundation, occupation and destruction are known these will be contained in the data base. This allows a map to be extracted for any specific year in history. The first issue of the map is essentially based on published sheets of the Tabula Imperii Romani and will thus cover the period of existence of the Roman Republic and Empire (ca. 500 BC to 500 AD). In principal there need be no limitation on the temporal coverage.
The map covers all military, civil, economic and cultural functions known for any geographical position. Each function has a designated order of importance which allows functions of a specific order to be printed only for a map of a given scale. See the list of Symbols for the functions currently covered.
If the interested reader would like to obtain a printout of the map at a scale differing from those provided or with a subset of functions or for a specific period in time he or she might address this wish to the authors.
The prime aim is of course to extend the spatial coverage of the atlas as fast as possible. The next sheets to be published will probably cover TIR sheets M-30 and M-31 (Londinium and Lutetia). At the same time the depth of information on published sheets might also grow, specifically the information on time ranges is currently sparse. There are two major object types missing from the map: roads and boundaries. These should also be added as soon as a respective data type has been defined.