Several authors have identified and proposed a terminology for representation of the 3D cadastre and ontologies are underway to further define the content and relationship in a 3D
A 3D cadastre is a cadastre that registers and gives insight into rights and restrictions on parcels as well as on 3D property units (Stoter & Oosterom, 2006). 3D cadastre is emerging as an effective means to support land space for using urban land in a way of three dimensions(Guo et al., 2011).
The right of ownership of a parcel has a 3D component. This becomes obvious when the upper and lower boundaries of the right lead to dispute, i.e., when more than one person uses the parcel. Actually, the right of ownership to a parcel (as all other real rights) always relates to a space; otherwise the use of the parcel would be impossible (Stoter & Oosterom, 2006).
The term “3D cadastre” can be interpreted in many ways ranging from a full 3D cadastre supporting volume parcels, to the current cadastre in which limited information is maintained on 3D situations. Here three fundamental concepts are distinguished (with several alternatives): the most advanced solution, the simplest solution, and one in between in which 3D situations are still registered within current cadastral and technical frameworks(Stoter & Oosterom, 2006).
3D cadastral object are features which concern urban planning, land resource and real estate of municipalities, whether they are on, above or below the earth’s surface. In essence, the 3D cadastral objects are the content and partition of urban geographic space, and they aim at registering legal status and property rights associated with land and other real estates or properties (Guo, Ying, 2010).
Several authors have identified and proposed a terminology for representation of the 3D cadastre and ontologies are underway to further define the content and relationship in a 3D object world. In principle three approaches can define the 3D (Stoter ; Oosterom, 2006):
1. Full 3D cadastral registration, where all space is subdivided into volumes with associated measurements and legal definitions and maintained as such; In a full 3D cadastre, a volumetric parcel is not necessarily visible in reality and only indirectly related to physical objects (Döner, Thompson, Stoter, et.al., 2011)
2. A hybrid solution, where all the cadastral layouts are maintained in a 2D space with associated measurements and legal definitions and established relationships to 3D physical objects;
3. 3D tagging, where all cadastral layouts are maintained in 2D with associated measurements and legal definitions and external references are made to the 3D data.
There are three ways to build 3D geometric primitives for 3D cadastre (Ying, Guo, Li, ; He, 2012): Firstly, extruding the existing 2D footprint or blueprint to get a 3D outer boundary (Ying, Li, Guo, 2011; Ledoux and Meijers, 2011). Secondly, a direct approach is to straightforward detect and recognize the valid 3D solids from the given 3D boundary facets. This processing needs a strict algorithm with the support of proper geometry and topology (Ying, Guo, Van Oosterom, et al., 2011). Thirdly, 3D cadastral models can be imported from 3D Building Information Models (BIM) or CityGML.
A 3D parcel is defined as the spatial unit with one or more unique and homogeneous rights (ownership right or land use right), responsibilities or restrictions (RRRs) are connected to the whole entity, as included in a Land Administration system (P. Oosterom, J. Stoter, H. Ploeger, 2014).
The development of land use has promote the land parcels to be subdivided in three dimensional (3D) space according to certain property rights, especially in urban area with dense population. This results in 3D parcels above or below the surface. To manage this 3D space becomes an vital task for the government, thus the representation and modelling of these 3D parcels with geometrical representation as solid in computer environment is to be handled (Ying, Guo, ; Li, 2011).
A 3D Cadastre can simplify communication of complex cases by providing 3D visualization tools to city staff, legal personnel and the public. These people are typically not 3D GIS experts and need simple tools to access the required information. Such an application needs to be very simple, work on a variety of hardware and operating systems and be easily maintained (Frédéricque ; Raymond, 2011).
3D modeling
First of all, geospatial modelling is the foundation for both GIS and cadastral systems. Comparing to the general modelling of common geographic features, such as road, block and building, 3D cadastral systems focus on creating 3D models of all cadastral objects, including 3D land parcels, 3D buildings, 3D property units and there collection. The particularity of each cadastral object is that it’s a geometric 3D primitive, which is a closed space that can be represented by a solid or a closed polyhedron. Also the 3D boundary of the cadastral objects should be accurate(Ying et al., 2012).
3D registration deals with maintaining spatial and non-spatial information on 3D objects, which are core themes of 3D GIS. Therefore, developments in 3D GIS are important when examining a 3D registration(Stoter & Oosterom, 2006).
3D GIS offers proper methods to represent the geometry of 3D cadastral objects and to associate the property rights, semantics and transaction attributes to them (Ying et al., 2012).
The geospatial and engineering industries have evolved very quickly over the past few years. The development of 3D GIS technologies offers new methods to represent property ownership in 3D and to associate detailed attribution to those representations.
Despite organizational and legal challenges, implementing a 3D Cadastre involves technical difficulties in order to create, maintain and share 3D information for cadastral registration (Frédéricque & Raymond, 2011).
Regarding to 3D cadastre, both GIS and CAD provide usefully implementing platforms and tools such as 3D modelling, data capturing, spatial data management, visualization and so on (Guo et al., 2011).
object world. In principle three approaches can define the 3D (Stoter & Oosterom, 2006):