(State Office for Cultural Heritage, Esslingen am Neckar, Germany)

Keywords: historical map, ALS, lidar

Historical maps are very valuable sources of information for understanding the past and for locating possible archaeological sites. However, due to various inaccuracies of such maps, many features shown on them can be difficult to locate. For example, many 18th century maps are based on a mix of survey methods (e.g. triangulation of important landmarks and less important places filled in based on walking distances or estimation) with very different error margins (from tens of metres to several kilometres). Standard methods for georeferencing therefore often result in maps which are severely distorted or in which only the well-surveyed points (usually those considered important at the time) are shown in the correct location. Features like roads, stream channels or artificial ponds (including commonly associated features such as bridges, gallows or mills) which are often depicted on historical maps can be very important from an archaeological point of view. However, their exact location may have been unimportant (or unknown) to the creator of the map. Interpretation of ALS (airborne lidar) visualisations can in many cases provide the necessary information to locate such features shown on historical maps. On the other hand, historical maps can support the interpretation of ALS visualisations. In many cases (and in particular for maps predating the 19th century), time and effort for a combined interpretation of historical maps and ALS visualisations are high.

Relevance conference | Relevance round table:
This paper relates to the theme of the conference by looking at both historical and new data (maps and ALS) in the context of the interconnections between settlements.