Claus Nagel

A multilayered space-event model for navigation in indoor spaces

In this paper a new conceptual framework for indoor navigation is proposed. While route planning requires models which reflect the internal structure of a building, localization techniques require complementary models reflecting the characteristics of sensors and transmitters. Since the partitioning of building space differs in both cases, a conceptual separation of different space models into a multilayer representation is proposed. Concrete space models for topographic space and sensor space are introduced. Both are systematically subdivided into primal and dual space on the one hand and (Euclidean) geometry and topology on the other hand. While topographic space describes 3D models of buildings and their semantically subdivisions into storey’s and rooms, sensor space describes the positions and ranges of transmitters and sensors like Wi-Fi access points or RFID sensors. It is shown how the connection of the different layers of the space models describe a joint state of a moving subject or object and reduces uncertainty about its current position.

Making interoperability persistent : A 3D geo database based on CityGML

Virtual 3D city models are becoming increasingly complex with respect to their spatial and thematic structures. CityGML is an OGC standard to represent and exchange city models in an interoperable way. As CityGML datasets may become very large and may contain deeply structured objects, the efficient storage and input/output of CityGML data requires both carefully optimized database schemas and data access tools. In this paper a 3D geo database for CityGML is presented. It is shown how the CityGML application schema is mapped to a relational schema in an optimized way. Then, a concept for the parallelized handling of (City)GML files using multithreading and the implementation of an import and export tool is explained in detail. Finally, the results from a first performance evaluation are given.

Advances in 3D Geo-Information Sciences

During the last decade developments in 3D Geoinformation have made substantial progress. We are about to have a more complete spatial model and understanding of our planet in different scales. Hence, various communities and cities offer 3D landscape and city models as valuable source and instrument for sustainable management of rural and urban resources. Also municipal utilities, real estate companies etc. benefit from recent developments related to 3D applications. To meet the challenges due to the newest changes academics and practitioners met at the 5th International Workshop on 3D Geoinformation in order to present recent developments and to discuss future trends. This book comprises a selection of evaluated, high quality papers that were presented at this workshop in November 2010. The topics focus explicitly on the last achievements (methods, algorithms, models, systems) with respect to 3D geo-information requirements. The book is aimed at decision makers and experts as well at students interested in the 3D component of geographical information science including GI engineers, computer scientists, photogrammetrists, land surveyors, urban planners, and mapping specialists.

Integrated 3D Modeling of Multi-utility Networks and Their Interdependencies for Critical Infrastructure Analysis

In today’s technologically advanced society the dependency of every citizen and company on working infrastructures is extremely high. Failures of critical infrastructures, such as the Italian blackout in 2003 or the failure of power supply in wide parts of Europe in 2006, demonstrate the strong linkage of networks across borders. However, also infrastructures within the same geographic region but of different types have strong interdependencies and failures in one type of network can have cascading effects onto the other networks. In order to support risk analysis and planning of emergency response actions the modeling of critical infrastructures and their mutual dependencies in 3D space is required. Decision makers need a comprehensive view of the disaster situation to be able to estimate the consequences of their action. For this purpose, a comprehensive understanding and simulation of cascading or looping effects as well as the propagation of the disaster extend is needed. But neither the existing utility networks models nor the international standards for modeling cities or buildings map the mutual interrelationships between different infrastructures or between the city and its infrastructures.

Supporting Contexts for Indoor Navigation Using a Multilayered Space Model

Indoor navigation highly depends on context and requires flexible data structures to support the many use cases and configurations. For example, an indoor navigation system must cope with different localisation techniques, infrastructures, and capabilities of mobile devices. Also physical constraints from the built-up environment, different modes of navigation (like walking, driving, or flying), and thematic restrictions like security zones have to be considered. In this paper we propose a novel modelling framework for indoor navigation which considers the aspects of route planning for different modes of navigation on the one hand and of various localisation techniques on the other hand. It is based on a structured and multilayered space model in which every type of physical or logical aspect is mapped within its own space layer. It is shown how layers can be combined according to concrete navigation contexts to build an n-partite graph facilitating both route planning and localisation.

Modelling 3D Topographic Space Against Indoor Navigation Requirements

Indoor navigation is growing rapidly with widespread developments in the collection and processing of sensor information for localisation and in routing algorithms calculating optimal indoor routes. However, there is a general lack of understanding about the requirements for topographic space information to be used in indoor navigation applications and thus the suitability of existing information sources. This work presents a structured process for the identification of topographic space information starting with use cases that support the complete capture of requirements, thus allowing existing models to be evaluated against these requirements and conceptual semantic and constraint models developed. A proposal is put forward for the implementation of topographic space semantic and constraints models as a CityGML Application Domain Extension (ADE) that will be integrated into the Multilayered Space-Event Model (MLSEM), a flexible framework supporting all indoor navigation tasks.

Semantic 3D Modeling of Multi-Utility Networks in Cities for Analysis and 3D Visualization

Precise and comprehensive knowledge about 3D urban space, critical infrastructures, and belowground features is required for simulation and analysis in the fields of urban and environmental planning, city administration, and disaster management. In order to facilitate these applications, geoinformation about functional, semantic, and topographic aspects of urban features, their mutual dependencies and their interrelations are needed. Substantial work has been done in the modeling and representation of aboveground features in the context of 3D city and building models. However, standardized models such as CityGML and IFC lack a rich information model for multiple and different underground structures. In contrast, existing utility network models are commonly tailored to a specific type of commodity, dedicated to serve as as-built documentation and thus are not suitable for the integrated representation of multiple and different utility infrastructures. Moreover, the mutual relations between networks as well as embedding into 3D urban space are not supported. The Utility Network ADE of CityGML as proposed in 2011 provides the required concepts and classes for the integration of multi-utility networks into the 3D urban environment. While the core model covers only the topological and topographic representation of network entities, the functional and semantic classification of network objects is now introduced in this paper. This paper will show how concepts and classes can be defined to fulfill the requirements of complex analyses and simulation, and how properties of specific networks can be defined with respect to 3D topography but also network connectivity and functional aspects.

3DCityDB - a 3D geodatabase solution for the management, analysis, and visualization of semantic 3D city models based on CityGML

Over the last decade, more and more cities and even countries worldwide are creating semantic 3D city models of their physical environment based on the international CityGML standard issued by the Open Geospatial Consortium (OGC). CityGML is an open data model and XML-based data exchange format describing the most relevant urban and landscape objects along with their spatial and non-spatial attributes, relations, and their complex hierarchical structures in five levels of detail. 3D city models, which are structured according to CityGML, are often used for various complex GIS simulation and analysis tasks, which go far beyond pure 3D visualization. Due to the large size and complexity of the sometimes country-wide 3D geospatial data, the GIS software vendors and service providers face many challenges when building 3D spatial data infrastructures for realizing the efficient storage, analysis, management, interaction, and visualization of the 3D city models based on the CityGML standard. Hence, there has been strong demand for an open and comprehensive software solution that can provide full support of the aforementioned functionalities. The ‘3D City Database’ (3DCityDB) is a free 3D geo-database solution for CityGML-based 3D city models. 3DCityDB has been developed as an Open Source and platform-independent software suite to facilitate the development and deployment of 3D city model applications. The 3DCityDB software package consists of a database schema for spatially enhanced relational database management systems (ORACLE Spatial or PostgreSQL/PostGIS) with a set of database procedures and software tools allowing to import, manage, analyze, visualize, and export virtual 3D city models according to the CityGML standard. Within this paper, the software suite is illustrated and explained in detail with respect to the related technical implementations and the underlying conceptual software design. Moreover, the utilization of 3DCityDB in different projects and practical application fields are also presented in this paper.