Automated generalisation in digital and mobile cartography

The variety of cartographic presentations of spatial and non spatial information has been significantly extended through web mapping and applications for mobile devices. The habilitation thesis in hand presents current research results on the automated derivation of digital, cartographic presentations with a major focuss on automated generalisation. The introductory sections describe challenges of modern cartography embedded in the context of geovisualisation and geoinformation sciences. Furthermore, current developments are shown in relation to the conventional topographic map production. These are characterised through a transition from paper map production towards GIS based cartography utilising multirepresentation databases. With that, prerequisites are given for an efficient data update process and the flexible consideration of different usage scenarios and user requirements. Exemplary applications of location-based services are presented and special requirements on mobile cartography are explained. The main part of this habilitation thesis is dedicated to research on the area of automated generalisation. During the definition of terms, generalisation is explained by the concept of abstraction. With that the task of automated generalisation is considered in a wider sense, besides the preservation of legibility constraints the major focuss is set on purpose orientation and user specific derivation of cartographic presentation. The discussion of previous generalisation research is carried out by a comparison of selected conceptual and technical frameworks. Furthermore, a categorisation and analysis is made of research presented at Generalisation Workshops of the ICA Commission on Generalisation and Multiple Representation to illustrate current and future research topics. The research publications integrated in this habilitation thesis cover several thematic topics. They present new methods and approaches which support both automated production of topographic maps as well as cartographic presentation on mobile devices. At the beginning it will be shown that the concept of Webserivces can be applied successfully to offer generalisation functionality independent of platform in a modular and hierarchically structured form. Following that methods are proposed for the modelling and analysis of cartographic requirements through constraints. Besides the formalised description of object properties the explicit modelling of relations between object representations are also essential for a successful automated generalisation. In this thesis two new generalisation algorithms will be introduced on the basis of different optimisation methods (snakes and mesh simplification). In particular the typification approach supports the generalisation of topographic maps, e.g. the typification of buildings, but can also be applied within mobile applications such as for the conflict free presentation of Points of Interest. Finally research question are investigated in the context of mobile information systems. A process chain is used to geo-enable spatial and non-spatial data making them available for locationbased services. Real-time requirements for cartographic presentation within this context can be satisfied through the usage of hierarchical data structures. In the subsequent discussion results and limitations of the presented approaches are worked out in a holistic view. There it is shown, that selected solutions can be transferred from the traditional cartographic domain to mobile cartography. The outlook enumerates possible future research topics, induced through the extended application of new technologies such as mobile information systems, positioning techniques, service oriented architectures, interaction possibilities and multimedia. New developments attempt on extending the standardised, universal information exchange on the basis of topographic maps with specialised, user centered presentation of spatial and non-spatial information