Standardization in land administration domain has been expanded to 3D and even 4D representations, adopting a multipurpose character, in order to become the foundation of a sustainable and smart economic development. At the moment, although the potential benefits of 3D Cadastre is argued to be enormous and there are plenty of standards related to 3D Cadastre while others enhancing the role of 3D Cities, there is no complete solution for 3D Cadastre. That being so, the last years, there has been a rapid increase in the integration, harmonization and implementation support of such standards. In this context, the integration of 3D legal spaces with 3D physical objects is gaining ground, as the (invisible) legal boundaries do not always match with the physical counterparts, leading to obscure situations. LADM, the International Standard for land administration, was proved to be one of the best candidates to unambiguously represent 3D Rights, Restrictions and Responsibilities. On the other side, spatial data models and virtual city models manage 3D urban structures without focusing on legal aspects. Many researchers have explored integrations between those aspects giving promising results. In this direction, apart from international standards, also national standards have been developed to enable the communication between land information systems. One of the most representatives is INTERLIS, a Swiss standard, a precise, standardized Object Relational modelling language on the conceptual level, which allows for automated quality control. Thus, in this paper the focus is given on how INTERLIS and LADM complement each other in the actual implementation of land administration systems. Main challenges among others in the context of this research include: 1. extensible hierarchical and versioned code lists in INTERLIS models, 2. formally define LADM constraints in INTERLIS, 3. discuss 3D geometry types and 4. introduce a holistic LADM/INTERLIS approach for country profiles.@en

The Land Administration Domain Model (LADM) is one of the first ISO spatial domain standards, and has been proven one of the best candidates for unambiguously representing 3D Rights, Restrictions and Responsibilities. Consequently, multiple LADM-based country profile implementations have been developed since the approval of LADM as an ISO standard; however, there is still a gap for technical implementations. This paper summarizes LADM implementation approaches distilled from relevant publications available to date. Models based on land administration standards do focus on the legal aspects of urban structures; however, the juridical boundaries in 3D are sometimes (partly) bound by the corresponding physical objects, leading to ambiguous situations. To that end, more integrated approaches are being developed at a conceptual level, and it is evident that the evaluation and validation of 3D legal and physical models—both separately and together in the form of an integrated model—is vital. This paper briefly presents the different approaches to legal and physical integration that have been developed in the last decade, while the need for more explicit relationships between legal and physical notions is highlighted. In this regard, recent experience gained from implementing INTERLIS, the Swiss standard that enables land information system communications, in LADM-based country profiles, suggests the possibility of an integrated LADM/INTERLIS approach. Considering semantic interoperability within integrated models, the need for more formal semantics is underlined by introducing formalization of code lists and explicit definition of constraints. Last but not least, the first results of case studies based on the generic LADM/INTERLIS approach are presented.@en

The massive developments and uses of high-rise buildings indicate that the demand for use of space above and below the ground surface is rapidly increasing in recent years. The same applies to Greece, where the existing cadastral model does not cover the 3D needs and does not conform to international standards. In this paper, a model is proposed, considered as an effort for overcoming these shortcomings, based on international standards, including the representation of a wide range of different types of spatial units, organized in levels according to the LA_Level structure of ISO19152 LADM. It is a proposal for a comprehensive multipurpose LAS supporting 2D and 3D cadastral registration in Greece. A prototype system was developed to exploit the strengths and limitations of the proposed conceptual model, as well as to investigate the efficiency of technological tools. Experience from the prototype will be used to further improve the conceptual model. The steps that were followed were: the description of the prototype in UML diagrams, the implementation via INTERLIS, a Swiss standard modeling language for geodata exchange, the selection of the most appropriate technical model/format to implement and visualize the result in 3D environment and finally the conversion and/or creation of sample data into the model. In this paper it is explored how INTERLIS can be used in actual implementation of land administration system based on LADM. During the development of the prototype many design decision have been taken and these are then analyzed, together with technical problems and challenges for future work.

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Building Information Models (e.g. BIM, IFC) and virtual 3D city models (e.g. CityGML) are revolutionising the way we manage information about cities. The main focus of such models is on the physical and functional characteristics of urban structures (Aien et al, 2015). On the other hand cadastral data models, (e.g. Land Administration Domain Model (LADM)), have been developed for legal information modelling and management purposes without providing correspondence to the object’s physical counterperts. However, by definition, those two aspects need to be interrelated; i.e. a tunnel, a building, a mine, etc. always have both a legal status and boundaries as well as a physical description; while it is evident that their integration would maximise their utility and flexibility to support different applications. In order to examine the correlation between those aspects, a prototype system was developed based on model driven architecture practices, empahasizing in formalization of constraints. Constraints have been proved effective in providing solutions needed to avoid errors and enable maintenance of data quality; thus the need to specify and implement them is vital. The paper explores possibilities of linking 3D legal right, restriction, responsibilities (RRR) spaces, modelled with LADM (LADM, ISO 19152), with physical reality of 3D objects (described via CityGML, IFC, InfraGML, etc). During this implementation, INTERLIS, a standard modelling language for geodata exchange, was selected as modelling language, because of its claimed good support of constraints in vendor neutral manner and ease of obtaining actual implementation. The system’s development cycle, from conceptual model to implementation of working prototype is illustrated through a proposed model for a Multipurpose Land Administation System (MLAS) for Greece. The prototype is developed in order to evaluate the strengths and limitations of the proposed conceptual model, as well as to investigate the efficiency and limitations of the existing technological (INTERLIS) tools. The process followed during the prototype development is cyclical and repetitive, providing feedback to the initial model during all the stages and improving it in terms of efficiency, reality and technical implementation. Main challenges among others during the system’s development cycle include the following: 1. how to express various LADM constraints (OCL and semiformal in standard) formally in INTERLIS, 2. how to include extensible hierarchical code lists in INTERLIS models (not natively available) and distinguish them from enumeration values, 3. how to model 3D volumetric primitives in INTERLIS (not natively available) and 4. how to link two models (legal - physical) using cross domain constraints. @en