Dubravka Sladic

Ontology for real estate cadastre

Abstract Standardisation efforts in the geospatial domain, provided by ISO TC 211 and OpenGIS Consortium, have brought many specifications and standards that define structure and encoding rules of data and interfaces of services. These standards provide syntactic interoperability of geospatial data and services, while neglecting their semantics. In order to achieve semantic interoperability, i.e. explicitly define the meaning of data and services to make them understandable both to machines and humans, there are attempts to develop Geospatial Semantic Web, where semantics of data will be expressed explicitly and formally. An important part of this process is the development of domain ontologies, i.e. a common vocabulary in some domain. In order to bring semantics into cadastral systems, it is necessary to develop ontology for real estate cadastre. Therefore, the authors propose the ontology based knowledge model in the field of real estate cadastre based on ISO 19152 international standard and other geospatial standards, as a core ontology for cadastre on top of which a domain ontology for a specific country should be built. The domain ontology presented in this paper refers to the real estate cadastre of Serbia, but a similar approach can be adopted for different cadastral organisations in other countries. In this way, different domain ontologies based on various cadastral organisations will conform to the same standard based core ontology that will provide a basis for the semantic search and integration of cadastral data on national and international level.

Semantic metadata in spatial information systems

Standardization in the field of GIS has led to a series of specifications and standards that define structure and encoding rules of data and interfaces of services provided by ISO TC 211 (ISO 19100 series) and OpenGIS Consortium. This set of standards provides syntactic interoperability of geospatial data and services, but does not solve semantic problems. In order to achieve semantic interoperability i.e. explicitly define the meaning of data and services to make them understandable both to machines and humans, attempts are made to develop geospatial semantic web, where not only the structure of data will be visible but semantics as well. In this process, particular attention is drawn to various domains such as environmental modeling or observations and measurements, but there are few results in the field of land administration that only address the problem partially and are not coordinated with standards. Therefore, the authors develop the ontology based knowledge model in the field of real estate cadastre coordinated with standards and propose how to reference resources to knowledge model concepts by annotating catalogue metadata and data models.

Spatial analysis of high-resolution urban thermal patterns in Vojvodina, Serbia

Main objective of this study was to establish a relationship between land cover and land surface temperature (LST) in urban and rural areas. The research was conducted using Landsat, WorldView-2 (WV-2) and Digital Mapping Camera. Normalised difference vegetation index and normalised difference built-up index were used for establishing the relation between built-up area, vegetation cover and LST for spatial resolution of 30 m. Impervious surface and vegetation area generated from Digital Mapping Camera from Intergraph and WV-2 were used to establish the relation between built-up area, vegetation cover and LST for spatial resolutions of 0.1, 0.5 and 30 m. Linear regression models were used to determine the relationship between LST and indicators. Main contribution of this research is to establish the use of combining remote sensing sensors with different spectral and spatial resolution for two typical settlements in Vojvodina. Correlation coefficients between LST and LST indicators ranged from 0.602 to 0.768.

Software architecture for semantically enhanced composition of geoservices in cadastral systems

This paper presents the software architecture for the composition of geoservices that are used for the discovery, access, processing and visualisation of spatial data in the cadastral systems. The architecture is based on the current standards in the field of GIS and information technologies in general. In order to solve semantic problems, the process of service composition is enhanced with the ontologies for data and services in the cadastral systems which enable (semi)automation of the composition process.

Domain model for cadastral systems with land use component

Well-structured and organised cadastral records and cadastral maps are a prerequisite for improving land administration services. In recent years, numerous problems and issues associated with cadastral data have been encountered in Serbia and attempts to overcome these problems have been made. The integration of land registry data with cadastral data containing land use component usually results in inconsistencies in land administration databases. To address this problem, an appropriate domain model has been developed using the Unified Process methodology and considering the land administration domain model and other ISO 19000 standards. Examples of verifying land administration data integrity in relational and object-oriented data models are presented. GRAPHICAL ABSTRACT

Towards 3D Cadastre in Serbia: Development of Serbian Cadastral Domain Model

This paper proposes a Serbian cadastral domain model as the country profile for the real estate cadastre, based on the Land Administration Domain Model (LADM), defined within ISO 19152. National laws and other legal acts were analyzed and the incorrect applications of the law are outlined. The national “Strategy of measures and activities for increasing the quality of services in the field of geospatial data and registration of real property rights in the official state records”, which was adopted in 2017, cites the shortcomings of the existing cadastral information system. The proposed profile can solve several problems with the system, such as the lack of interoperability, mismatch of graphic and alphanumeric data, and lack of an integrated cadastral information system. Based on the existing data, the basic concepts of the Serbian cadastre were extracted and the applicability of LADM was tested on an obtained conceptual model. Upon obtaining positive results, a complete country profile was developed according to valid national laws and rulebooks. A table of mappings of LADM classes and country profile classes is presented in this paper, together with an analysis of the conformance level. The proposed Serbian country profile is completely conformant at the medium level and on several high-level classes. LADM also provides support for three-dimensional (3D) representations and 3D registration of rights, so the creation of a country profile for Serbia is a starting point toward a 3D cadastre. Given the existence of buildings with overlapping rights and restrictions in 3D, considering expanding the spatial profile with 3D geometries is necessary. Possible solutions to these situations were analyzed. Since the two-dimensional (2D) cadastre in Serbia is not fully formed, the proposed solution is to use the 2D model for simple right situations, and the 3D model for more complex situations.

Geospatial Web Services in Real Estate Information System

Since the data of cadastral records are of great importance for the economic development of the country, they must be well structured and organized. Records of real estate on the territory of Serbia met many problems in previous years. To prevent problems and to achieve efficient access, sharing and exchange of cadastral data on the principles of interoperability, domain model for real estate is created according to current standards in the field of spatial data. The resulting profile of the domain model for the Serbian real estate cadastre is based on the current legislation and on Land Administration Domain Model (LADM) which is specified in the ISO19152 standard. Above such organized data, and for their effective exchange, it is necessary to develop a model of services that must be provided by the institutions interested in the exchange of cadastral data. This is achieved by introducing a service-oriented architecture in the information system of real estate cadastre and with that ensures efficiency of the system. It is necessary to develop user services for download, review and use of the real estate data through the web. These services should be provided to all users who need access to cadastral data (natural and legal persons as well as state institutions) through e-government. It is also necessary to provide search, view and download of cadastral spatial data by specifying geospatial services. Considering that real estate contains geometric data for parcels and buildings it is necessary to establish set of geospatial services that would provide information and maps for the analysis of spatial data, and for forming a raster data. Besides the theme Cadastral parcels, INSPIRE directive specifies several themes that involve data on buildings and land use, for which data can be provided from real estate cadastre. In this paper, model of geospatial services in Serbia is defined. A case study of using these services to estimate which household is at risk of flooding using the Web Processing Service (WPS) spatial analysis is described.