3D Cadastres Best Practices, Chapter 5: Visualization and New Opportunities

This paper proposes a discussion on opportunities offered by 3D visualization to improve the understanding and the analysis of cadastre data. It first introduce the rationale of having 3D visualization functionalities in the context of cadastre applications. Second the publication outline some basic concepts in 3D visualization. This section specially addresses the visualization pipeline as a driven classification schema to understand the steps leading to 3D visualization. In this section is also presented a brief review of current 3D standards and technologies. Next is proposed a summary of progress made in the last years in 3D cadastral visualization. For instance, user’s requirement, data and semiotics, and platforms are highlighted as main actions performed in the development of 3D cadastre visualization. This review could be perceived as an attempt to structure and emphasise the best practices in the domain of 3D cadastre visualization and as an inventory of issues that still need to be tackled. Finally, by providing a review on advances and trends in 3D visualization, the paper initiates a discussion and a critical analysis on the benefit of applying these new developments to cadastre domain. This final section discusses about enhancing 3D techniques as dynamic transparency and cutaway, 3D generalization, 3D visibility model, 3D annotation, 3D data and web platform, augmented reality, immersive virtual environment, 3D gaming, interaction techniques and time

The application of visualisation techniques for stratum and strata boundaries within the New South Wales digital cadastre

Population growth and trends towards urban consolidation have lead to a change in cadastral definition within the Greater Sydney area as high-density mixed-use buildings becoming more prominent. This has lead to increased potential of conflicts between end-users regarding boundary locations and the associated rights, restrictions and responsibilities and the vertical subdivisions are used to alleviate potential sources of conflict within developments in the form of stratum subdivisions, Torrens title lots with vertical restrictions, and strata subdivisions, strata lots existing within a scheme. However due to the complexity of these plans, specifically stratum subdivisions, the usability for the end-user is limited without access to surveying knowledge and practices. This dissertation sought to investigate the use of 3D visualisation within digital cadastral mapping to improve the end-users experience with understanding height limited boundaries and the relationship between lots within stratum subdivisions. Through the investigation of three case studies, each representing a different density of development with stratum subdivisions, and the modelling of the lots in Google Earth the research demonstrated how the use of 3D models improves the comprehension and ability to access spatial data through digital cadastral maps. The outcomes of this research suggest that the use of 3D models for height limited parcels can improve digital mapping and not to replace traditional surveying plans but provide a parallel format that is more user-friendly than the survey plan on its own

Developing Serbian 3D Cadastre System - Challenges and Directions

The real estate cadastre in the Republic of Serbia is based on 2D cadastral maps and procedures that do not support unequivocal registration and visualization of complex 3D property situations or complex objects located on/below several parcels, especially in urban areas. Within this study, we analyzed and documented specific situations concerning registration challenges for the current cadastral system in the Republic of Serbia.Furthermore, the analysis of additional functionalities which will enable overcoming the limitations of the current cadastre in the short to the medium-termtime period is represented. Themain objective is to use the current cadastral data and procedures as far as possible in order to keep the transition smoother and economicallyfeasible. Having in mindthis objective,thevariation ofthe hybridapproach as the solution for Serbian 3D real estate cadastrewas analyzed. One of the preliminary assumptions of this research is that it is possible to develop a systemthat is simple enoughforimplementationand maintenance,but at the same comprehensive enough to overcome the difficulties ofthe current real estate cadastre.Within the case study,3D objects based ondata currently provided by licensed surveying agenciesare presented

Initial Registration of 3D Parcels

Registering the rights of a 3D parcel provides certainty of ownership, protection of rights and unambiguous spatial location. While not all cadastral jurisdictions in the world maintain a digital cadastral database, the concepts of such registration hold true regardless of whether it is a paper-based cadastre or a digital one. Similarly, the motivations and purpose for the creation of a 2D cadastre for individual jurisdictions applies for 3D cadastres as well. It provides a security of ownership of 3D parcel, protects the rights of the owners, and provides valuable financial instruments such as mortgage, collateral, valuation and taxation. The current life cycle of the development of a land parcel includes processes beginning from outside the cadastral registration sphere, such as zoning plans and permits, but has a direct impact on how a certain development application is processed. Thus, in considering the changes required to allow a jurisdiction to register 3D, it is important to note the sphere of influence that could have an impact on 3D registration. These include planners, notaries, surveyors, data managers and registrars; however for the purpose of this paper, the research is focused on the core 3D aspects that are institutional, legal and technical. This paper explores approaches and solutions towards the implementation of initial 3D cadastral registration, as derive by current procedures of registration of 3D parcels in various countries worldwide. To this purpose, the paper analyses the categorisations and approaches to 3D spatial units and examines the validation requirements (constraints) on a cadastral database, at various levels of maturity. In this view, 3D data storage and visualization issues are examined in relation to the level of complexity of various jurisdictions, as provided by the results of the country inventory combined with a worldwide survey in 2010 and updated in 2014 (Van Oosterom, et al, 2014). It seems that significant progress has been achieved in providing legal provisions for the registration of 3D cadastres in many countries and several have started to show 3D information on cadastral plans such as isometric views, vertical profiles or text environment to facilitate such data capture and registration. Moreover, as jurisdictions progress towards an implementation of 3D cadastres, much 3D data collected in other areas (BIM, IFC CityGML files, IndoorGML, InfraGML and LandXML) open up the possibility of creating 3D cadastral database combining the existing datasets. The usability, compatibility and portability of these datasets is a low cost solution to one of the costliest phases of the implementation of 3D cadastres, which is the initial 3D data capture

An investigation into LandXML for implementation of 3D Cadastre in eSurvey

With the rapid growth of urban environments including the increasing complexity of infrastructures, there is an urgent need to develop more innovative and efficient land administration systems. Many countries, including Australia, are now developing and implementing three dimensional (3D) cadastral frameworks to address these situations, but capturing and registering these rights within existing systems brings considerable challenges. In Australia, the existing approach of registering 3D rights and storing partial geometry in databases does not support 3D functionalities such as 3D validation, query, visualisation, and manipulation. The existing Digital Cadastral Data Base (DCDB) does not support the storage of 3D data. There is also no digital lodgement of 3D cadastral, and no automated validation (Karki, 2013). The Intergovernmental Committee of Surveying and Mapping (ICSM) has endorsed LandXML as the national standard for digital lodgement of cadastral plans. LandXML is an extensible mark-up language (XML) package which can be used for exchanging spatial information. In Queensland Surveying information is captured digitally using tools built in-house, such as the Surveying Information Processing (SIP) tool which is based on LandXML and is used to electronically capture a paper based cadastral plans. The Electronic Access for Registry Lodgement (eSurvey, previously called EARL) project is developed and run by the Department of Natural Resources and Mines (DNRM) and it has three stages namely eSurvey-I, eSurvey-II, and eSurvey-III. The eSurvey Services Portal allows users to submit, validate and visualise survey data via Web Services. eSurvey-I developed a tool for internal DNRM use to digitally capture the information on a survey plan. eSurvey-II has developed a validation tool that will be applied to Cadastral Information Files (CIFs) that are submitted to the Department by external surveyors as a component of the digital lodgement of survey plans process. eSurvey-III will be the full digital lodgement and implementation of electronic capture and visualisation of 3D cadastral data where the digital files become the legal document. The objective of this research is to explore the capability of LandXML for the definition of 3D spatial objects within the eSurvey project for 3D Cadastre development in Queensland. An overview of 3D Cadastre and characteristics of eSurvey, volumetric plans and LandXML were reviewed. Two representative cases from Queensland digital cadastral database were selected and examined using three standard CAD software and eSurvey web portal and Queensland DCDB standards. This study shows that eSurvey can successfully validate LandXML files

Visualisation and dissemination of 3D valuation units and groups:An LADM valuation information compliant prototype

The timely and effective dissemination of property values is an essential part of a transparent and efficient property valuation system. Over the last decade, web-based data-sharing systems have been increasingly used for the dissemination of assessed property values. 3D valuation units (e.g., condominium) and groups (aggregation of valuation units, e.g., a building floor in a multi-occupied building, a multi-occupied building, street, district or valuation zone) may be required to better communicate with users and to support a more effective and efficient dissemination. However, none of these systems share valuation information associated with 3D representation of the valuation units and groups. In this paper, a prototype of a web-based system is developed utilising the proposed Valuation Information part of the Edition II of the ISO 19152 Land Administration Domain Model compliant dataset for not only disseminating the spatial, physical, thematic and temporal characteristics of 3D valuation units, but also for sharing the valuation statistics at each designated level and with level-specific attributes. It is expected that the outcomes of this work may contribute to the development of local or national valuation systems and systems for geo-based data visualisation for effective and efficient sharing of valuation information. As such, it is anticipated that the study's outcomes will not only increase the level of communication with the public, but also support politicians and planners in their decision-making processes and help them to better analyse and understand the property market. With the proposed system, confidence in valuation results can be further increased due to the high level of transparency.Digital Technologie

The Millimeter Legal Coordinated Cadastre

Land ownership is an important part of a nation’s wealth. Land value is determined by information about the land and about property rights that exist over the land. The Cadastre is the primary means of providing information about property rights, providing the private and public sector with: information identifying those people who have interests in parcels of land; information about those interests; and information about the parcels. The definitive cadastre would require anyone looking for information about a parcel of land to only go to the cadastre to find everything there is to know about the land such as: • the exact, true location on the ground of all boundary corners of the parcel; • the exact, true measurements, such as direction and distance of all boundary lines of the parcel and the exact area and geometry of the parcel as it exists on the ground; • the exact, true information on every interest (and all interests) that exists over the parcel, including the person who owns the interest and the exact nature and extent of the interest. Examined in this thesis are issues surrounding the design of such an ultimate cadastre. One conclusion is that the ultimate cadastre should be based on the legal coordinated cadastre in which geodetic coordinates are used to define boundary corner locations. Also, since it is difficult to quantify what is meant by “exact”, this thesis will make the assumption that the smallest error of concern is 1 mm and thus the ultimate cadastre is the millimeter legal coordinated cadastre. Other conclusions are that the cadastre should be based on the Torrens system of land registration, but where all property rights are registered rather than just the ownership right known as the fee-simple estate. The millimeter legal coordinated cadastre is compared and found to be superior to other existing cadastres

3D visualization of cadastre : assessing the suitability of visual variables and enhancement techniques in the 3D model of condominium property units

La visualisation 3D de données cadastrales a été exploitée dans de nombreuses études, car elle offre de nouvelles possibilités d’examiner des situations de supervision verticale des propriétés. Les chercheurs actifs dans ce domaine estiment que la visualisation 3D pourrait fournir aux utilisateurs une compréhension plus intuitive d’une situation où des propriétés se superposent, ainsi qu’une plus grande capacité et avec moins d’ambiguïté de montrer des problèmes potentiels de chevauchement des unités de propriété. Cependant, la visualisation 3D est une approche qui apporte de nombreux défis par rapport à la visualisation 2D. Les précédentes recherches effectuées en cadastre 3D, et qui utilisent la visualisation 3D, ont très peu enquêté l’impact du choix des variables visuelles (ex. couleur, style) sur la prise de décision. Dans l’optique d'améliorer la visualisation 3D de données cadastres, cette thèse de doctorat examine l’adéquation du choix des variables visuelles et des techniques de rehaussement associées afin de produire un modèle de condominium 3D optimal, et ce, en fonction de certaines tâches spécifiques de visualisation. Les tâches visées sont celles dédiées à la compréhension dans l’espace 3D des limites de propriété du condominium. En ce sens, ce sont principalement des tâches notariales qui ont été ciblées. De plus, cette thèse va mettre en lumière les différences de l’impact des variables visuelles entre une visualisation 2D et 3D. Cette thèse identifie dans un premier temps un cadre théorique pour l'interprétation des variables visuelles dans le contexte d’une visualisation 3D et de données cadastrales au regard d’une revue de littéraire. Dans un deuxième temps, des expérimentations ont été réalisées afin de mettre à l’épreuve la performance des variables visuelles (ex. couleur, valeur, texture) et des techniques de rehaussement (transparence, annotation, déplacement). Trois approches distinctes ont été utilisées : 1) discussion directe avec des personnes œuvrant en géomatique, 2) entrevue face à face avec des notaires et 3) questionnaire en ligne avec des groupes ciblés. L’utilisabilité mesurée en termes d’efficacité, d’efficience et de degré de satisfaction a servi aux comparaisons des expérimentations. Les principaux résultats de cette recherche sont : 1) Une liste de tâches visuelles notariales utiles à la délimitation des unités de propriété dans le contexte de la visualisation 3D de condominium ; 2) Des recommandations quant à l'adéquation de huit variables visuelles et de trois techniques de rehaussement afin d’optimiser la réalisation d’un certain nombre de tâches notariales ; 3) Une analyse comparative de la performance de ces variables entre une visualisation 2D et 3D.3D visualization is being widely used in GIS (geographic information system) and CAD (computer-aided design) applications. It has also been introduced in cadastre studies to better communicate overlaps to the viewer, where the property units vertically stretch over or cover one part of the land parcel. Researchers believe that 3D visualization could provide viewers with a more intuitive perception, and it has the capability to demonstrate overlapping property units in condominiums unambiguously. However, 3D visualization has many challenges compared with 2D visualization. Many cadastre researchers adopted 3D visualization without thoroughly investigating the potential users, the visual tasks for decision-making, and the appropriateness of their representation design. Neither designers nor users may be aware of the risk of producing an inadequate 3D visualization, especially in an era when 3D visualization is relatively novel in the cadastre domain. With a general aim to improve the 3D visualization of cadastre data, this dissertation addresses the design of the 3D cadastre model from a graphics semiotics viewpoint including visual variables and enhancement techniques. The research questions are, firstly, what is the suitability of the visual variables and enhancement techniques in the 3D cadastre model to support the intended users' decision-making goal of delimitating condominium property units, and secondly, what are the perceptual properties of visual variables in 3D visualization compared with 2D visualization? This dissertation firstly identifies the theoretical framework for the interpretation of visual variables in 3D visualization as well as cadastre-related knowledge with literature review. Then, we carry out a preliminary evaluation of the feasibility of visual variables and enhancement techniques in a form of an expert-group review. With the result of the preliminary evaluation, this research then performs the hypothetico-deductive scientific approach to establishing a list of hypotheses to be validated by empirical tests regarding the suitability of visual variables and enhancement techniques in a cartographic representation of property units in condominiums for 3D visualization. The evaluation is based on the usability specification, which contains three measurements: effectiveness, efficiency, and preference. Several empirical tests are conducted with cadastral users in the forms of face-to-face interviews and online questionnaires, followed by statistical analysis. Size, shape, brightness, saturation, hue, orientation, texture, and transparency are the most discussed and used visual variables in existing cartographic research and implementations; thus, these eight visual variables have been involved in the tests. Their perceptual properties exhibited in the empirical test with concrete 3D models in this work are compared with those in a 2D visualization, which is derived from a literature-based synthesis. Three enhancement techniques, including labeling, 3D explosion, and highlighting, are tested as well. There are three main outcomes of this work. First, we established a list of visual tasks adapted to notaries for delimiting property units in the context of 3D visualization of condominium cadastres. Second, we describe the suitability of eight visual variables (Size, Shape, Brightness, Saturation, Hue, Orientation, Texture, and Transparency) of the property units and three enhancement techniques (labeling, 3D explosion and highlighting) in the context of 3D visualisation of condominium property units, based on the usability specification for delimitating visual tasks. For example, brightness only shows good performance in helping users distinguish private and common parts in the context of 3D visualization of property units in condominiums. As well, color hue and saturation are effective and preferable. The third outcome is a statement of the perceptual properties’ differences of visual variables between 3D visualization and 2D visualization. For example, according to Bertin (1983)’s definition, orientation is associative and selective in 2D, yet it does not perform in a 3D visualization. In addition, 3D visualization affects the performance of brightness, making it marginally dissociative and selective

Legal Coordinated Cadastres – Theoretical Concepts and the Case of Singapore

The field of cadastre holds an inherent complexity much based on its interdisciplinary characteristics and the national uniqueness of each cadastral system. In addition, some cadastral terminology is vague or ambiguous, why omission of the explicit sense and context of a particular term may bring obscurity to international comparisons and analyses. The concept legal coordinated cadastre, occasionally mentioned in connection with visions and plans of cadastral modernization, is discussed here in order to clarify possible meanings and implications. In an elaborate form, such a cadastre denotes that all property boundaries within a jurisdiction are legally defined by survey accurate coordinates guaranteed by the State. In less extensive forms, the coordinates in a digital cadastre are important means of evidence but they do not prevail over intact physical monuments on the ground. After an account of these theoretical issues, this paper presents the results of a case study of the recent cadastral reform in Singapore. The new Singaporean cadastre, effectuated in August 2004, is considered to be the first complete legal coordinated cadastre worldwide. This achievement involved great technical efforts as well as adjustments to the laws in force. For example, a new national reference system (SVY21) and a network of reference stations for GPS were established, enabling a systematic conversion of existing boundary data. When all boundaries were finally defined by SVY21 coordinates, the new cadastre was given legal significance according to the amended Boundaries and Survey Maps Act. From a legal perspective, this implies that the cadastral map coordinates are now conclusive evidence in court. The Chief Surveyor is however empowered to correct the cadastral map should it be defective due to e.g. errors in measuring or data conversion. Furthermore, the State does not guarantee the correctness of the cadastral boundary data, why the reliability of the coordinates is limited in some aspects. The Singaporean coordinated cadastre can hence be seen as a technically advanced system with a practical approach to the legal implications