## 2 Data and Methods  
The First Military Mapping survey of the Habsburg monarchy was carried out in Bohemia in the years 1764-1767. This incredibly short time was made possible by the fact that the mapping took place from the eye, only by officers on horseback. Enlargements of the [PERSON] map of Bohemia may have been used, which had been made in 1720 at a scale of approximately 1:132,000. The measuring table was probably used in part, the lengths were estimated or stepped. In particular, militarily important objects were mapped: roads, bridges, brick buildings, meadows, pastures, forests, or watercourses. The elevations shown on these maps are made by hachures. In winter, clean drawings of map sheets measuring 61.8 cm by 40.8 cm at a scale of 1:28,800 were created from the original maps created in the field. In addition to the map sheets, textual comments and military-geographical descriptions of the area were supplemented. In addition to 273 map sheets in Bohemia, 19 volumes of topographic descriptions of the landscape were made. Due to the imperfections of the maps, which were manifested in the was with Prussia in 1778 and 1779, the rectification of the most important (northern) map sheets was ordered. Thus, 141 map sheets were newly mapped and two map sheets were corrected. The differences between the older and rectified maps are not very obvious, for example, the drawing of forest areas differs slightly. Of course, all the resulting maps were confidential. The original map sheets are stored in the Osterreichisches Staatsarchiv--Kriegsarchiv. The J. E. Purkyne University in Usti nad Labem was involved in making these maps accessible [27]. We have a total of 273 raster images of maps of the first military mapping in a resolution of 400 dpi and a color depth of 24 bits (TIFF files without compression). The data volume of each sheet is more than 300 MB. The quality of this digital data is sufficient for most of the intended analyzes. A resolution of 600 dpi would be more appropriate for automatic image pattern searching, automatic text recognition, and other graphical operations. A good identification of the corners of map sheets and GCPs is crucial for georeferencing maps and creating continuous mosaics. However, identifying corners is very problematic. The map sheets have a marked map frame on the north and east sides only (see Figure 1). The northeast corner is, thus, clearly identifiable. For others, finding the exact point is problematic, most, of course, in the southwest corner, where it is only possible to infer its position according to the map drawing. Identifying GCPs is easier. In particular, permanently identifiable objects (churches, chapels, farmsteads etc.) were selected for georeferencing; if such objects were missing, then road intersections, sacral objects, or other map elements were selected. The current location of these objects was determined according to the state map work of the Czech Republic, or according to the already georeferenced Second Military Mapping. Out of 273 map sheets, only 250 were selected to create the mosaic. The remaining 23 map sheets are marginal areas where it is not possible to read the corners of the sheets well and the numbers of GCPs are insufficient on them. Therefore, they were excluded from these calculations. Their addition to the resulting mosaic is possible after individual georeferencing using a polynomial transformation. A total of 6849 GCPs were collected on 250 map sheets, averaging more than 27 points on the map sheet. In addition, a regular distribution within the maps was important (see Figure 2). For georeferencing, we chose a global method using the least squares method. In order for individual sheets to fit together, it was necessary to include conditions in the adjustment. The calculation of intermediate measurements with conditions is used for the calculation.