Rectification of the Romanian 1:75 000 map series, prior to World War I

The labelling system, the projection and the datum parameters of the sheets of the 1:75 000 scale Romanian topographic map series completed prior to World War I, are described in order to integrate them to GIS databases. The series has two zones, eastern and western, both on the Bonne projection with different parameters. The sheets from each zone should be handled in a slightly different way in order to rectify them. The eastern sheets can be rectified using the grid coordinates computed from the sheet labels of the corner points. In the case of the western zone sheets, the geographic coordinates are computed from the sheet labels or directly from the graticule corners reprojected on the respective Bonne projection. The abridged Molodenskyparameters for the datums of the two zones are also given. The rectified sheets integrated to a GIS database provide an interesting source of the natural and built environment of the early 20th century Romania