Topographic Signs: Important Context for a 3D Cadastre

Utilities, buildings and infrastructure digital representations are very important set of spatial data for quality and sustainable spatial management and development of community in general. Many countries are on the way of the establishment of the 3D cadastre. Existing 2D cadastral systems are able to make gradual transition to 3D cadastre, but for the implementation of real 3D cadastre in many countries it is necessary to change the regulations. A topographic sign or topographic symbol is representation of a topographic
object on map. In combination with other geodetic and cartographic products we can get to very useful information, often quite relevant in order to provide reference context for a 3D cadastre. Topographic signs on topographic maps and on other geodetic products give a representation of complex real-world situations that are not usually drawn in the cadastral maps. The real world, physical, objects as included on topographic maps, prove the context/
reference for the legal spaces. This is true for both the 2D, but perhaps even more for the 3D case. Performing an overlay, if needed after proper orientation, it is easy to combine geodetic and cartographic products in today’s digital environment. Special attention is needed for the tunnels, overpasses, underpasses, bridges and other objects to be registered in 3D cadastre
because their 2D cadastral description does not meet the needs of modern society. In case of 3D topographic data (e.g. 3D CityGML model), then it would also well possible to implement this into 3D cadastre and combine 3D legal spaces with the 3D real world items from the 3D topographical model. However, this combination/integration is usually not feasible with the cadastral plans (survey plans, field sketches) as those are not draws to scale (in both 2D and
3D).