@article{BuschmannTrappDoellner2016,
  author    = {Buschmann, Stefan and Trapp, Matthias and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Animated visualization of spatial-temporal trajectory data for air-traffic analysis},
  series = {The Visual Computer},
  volume    = {32},
  journal   = {The Visual Computer},
  publisher = {Springer},
  address   = {New York},
  issn      = {0178-2789},
  doi       = {10.1007/s00371-015-1185-9},
  pages     = {371 -- 381},
  year      = {2016},
  abstract  = {With increasing numbers of flights worldwide and a continuing rise in airport traffic, air-traffic management is faced with a number of challenges. These include monitoring, reporting, planning, and problem analysis of past and current air traffic, e.g., to identify hotspots, minimize delays, or to optimize sector assignments to air-traffic controllers. To cope with these challenges, cyber worlds can be used for interactive visual analysis and analytical reasoning based on aircraft trajectory data. However, with growing data size and complexity, visualization requires high computational efficiency to process that data within real-time constraints. This paper presents a technique for real-time animated visualization of massive trajectory data. It enables (1) interactive spatio-temporal filtering, (2) generic mapping of trajectory attributes to geometric representations and appearance, and (3) real-time rendering within 3D virtual environments such as virtual 3D airport or 3D city models. Different visualization metaphors can be efficiently built upon this technique such as temporal focus+context, density maps, or overview+detail methods. As a general-purpose visualization technique, it can be applied to general 3D and 3+1D trajectory data, e.g., traffic movement data, geo-referenced networks, or spatio-temporal data, and it supports related visual analytics and data mining tasks within cyber worlds.},
  language  = {en}
}
@article{DelikostidisEngelRetsiosetal.2013,
  author    = {Delikostidis, Ioannis and Engel, Juri and Retsios, Bas and van Elzakker, Corne P. J. M. and Kraak, Menno-Jan and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Increasing the usability of pedestrian navigation interfaces by means of landmark visibility analysis},
  series = {The journal of navigation},
  volume    = {66},
  journal   = {The journal of navigation},
  number    = {4},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {0373-4633},
  doi       = {10.1017/S0373463313000209},
  pages     = {523 -- 537},
  year      = {2013},
  abstract  = {Communicating location-specific information to pedestrians is a challenging task which can be aided by user-friendly digital technologies. In this paper, landmark visibility analysis, as a means for developing more usable pedestrian navigation systems, is discussed. Using an algorithmic framework for image-based 3D analysis, this method integrates a 3D city model with identified landmarks and produces raster visibility layers for each one. This output enables an Android phone prototype application to indicate the visibility of landmarks from the user's actual position. Tested in the field, the method achieves sufficient accuracy for the context of use and improves navigation efficiency and effectiveness.},
  language  = {en}
}
@article{DischerRichterDoellner2019,
  author    = {Discher, S{\"o}ren and Richter, Rico and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Concepts and techniques for web-based visualization and processing of massive 3D point clouds with semantics},
  series = {Graphical Models},
  volume    = {104},
  journal   = {Graphical Models},
  publisher = {Elsevier},
  address   = {San Diego},
  issn      = {1524-0703},
  doi       = {10.1016/j.gmod.2019.101036},
  pages     = {11},
  year      = {2019},
  abstract  = {3D point cloud technology facilitates the automated and highly detailed acquisition of real-world environments such as assets, sites, and countries. We present a web-based system for the interactive exploration and inspection of arbitrary large 3D point clouds. Our approach is able to render 3D point clouds with billions of points using spatial data structures and level-of-detail representations. Point-based rendering techniques and post-processing effects are provided to enable task-specific and data-specific filtering, e.g., based on semantics. A set of interaction techniques allows users to collaboratively work with the data (e.g., measuring distances and annotating). Additional value is provided by the system's ability to display additional, context-providing geodata alongside 3D point clouds and to integrate processing and analysis operations. We have evaluated the presented techniques and in case studies and with different data sets from aerial, mobile, and terrestrial acquisition with up to 120 billion points to show their practicality and feasibility.},
  language  = {en}
}
@article{DischerRichterDoellner2016,
  author    = {Discher, S{\"o}ren and Richter, Rico and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Interactive and View-Dependent See-Through Lenses for Massive 3D Point Clouds},
  series = {Advances in 3D Geoinformation},
  journal   = {Advances in 3D Geoinformation},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-25691-7},
  issn      = {1863-2246},
  doi       = {10.1007/978-3-319-25691-7_3},
  pages     = {49 -- 62},
  year      = {2016},
  abstract  = {3D point clouds are a digital representation of our world and used in a variety of applications. They are captured with LiDAR or derived by image-matching approaches to get surface information of objects, e.g., indoor scenes, buildings, infrastructures, cities, and landscapes. We present novel interaction and visualization techniques for heterogeneous, time variant, and semantically rich 3D point clouds. Interactive and view-dependent see-through lenses are introduced as exploration tools to enhance recognition of objects, semantics, and temporal changes within 3D point cloud depictions. We also develop filtering and highlighting techniques that are used to dissolve occlusion to give context-specific insights. All techniques can be combined with an out-of-core real-time rendering system for massive 3D point clouds. We have evaluated the presented approach with 3D point clouds from different application domains. The results show the usability and how different visualization and exploration tasks can be improved for a variety of domain-specific applications.},
  language  = {en}
}
@article{Doellner2005,
  author    = {D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Geospatial digital rights management in geovisualization},
  issn      = {0008-7041},
  year      = {2005},
  abstract  = {Geovisualization offers powerful tools, techniques, and strategies to present, explore, analyze, and manage geoinformation. Interactive geovirtual environments such as virtual 3D maps or virtual 3D city models, however, raise the question how to control geodata usage and distribution. We present a concept for embedding digital rights in geovisualizations. It is based on geo-documents, an object-oriented scheme to specify a wide range of geo visualizations. Geo-documents are assembled by building blocks categorized into presentation, structure, interaction, animation, and Digital Rights Management (DRM) classes. DRM objects allow for defining permissions and constraints for all objects contained in geo-documents. In this way, authors of geo visualizations can control how their geo-documents are used, personalized, and redistributed by users. The strengths of the presented concept include the ability to integrate heterogeneous 2D and 3D geodata within a compact design scheme and the ability to cope with privacy, security, and copyright issues. Embedded digital rights in geovisualizations can be applied to improve the usability of geodata user interfaces, to implement publisher-subscriber communication systems for geodata, and to establish business models for geodata trading systems},
  language  = {en}
}
@article{Doellner2020,
  author    = {D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Geospatial artificial intelligence},
  series = {Journal of photogrammetry, remote sensing and geoinformation science : PFG : Photogrammetrie, Fernerkundung, Geoinformation},
  volume    = {88},
  journal   = {Journal of photogrammetry, remote sensing and geoinformation science : PFG : Photogrammetrie, Fernerkundung, Geoinformation},
  number    = {1},
  publisher = {Springer International Publishing},
  address   = {Cham},
  issn      = {2512-2789},
  doi       = {10.1007/s41064-020-00102-3},
  pages     = {15 -- 24},
  year      = {2020},
  abstract  = {Artificial intelligence (AI) is changing fundamentally the way how IT solutions are implemented and operated across all application domains, including the geospatial domain. This contribution outlines AI-based techniques for 3D point clouds and geospatial digital twins as generic components of geospatial AI. First, we briefly reflect on the term "AI" and outline technology developments needed to apply AI to IT solutions, seen from a software engineering perspective. Next, we characterize 3D point clouds as key category of geodata and their role for creating the basis for geospatial digital twins; we explain the feasibility of machine learning (ML) and deep learning (DL) approaches for 3D point clouds. In particular, we argue that 3D point clouds can be seen as a corpus with similar properties as natural language corpora and formulate a "Naturalness Hypothesis" for 3D point clouds. In the main part, we introduce a workflow for interpreting 3D point clouds based on ML/DL approaches that derive domain-specific and application-specific semantics for 3D point clouds without having to create explicit spatial 3D models or explicit rule sets. Finally, examples are shown how ML/DL enables us to efficiently build and maintain base data for geospatial digital twins such as virtual 3D city models, indoor models, or building information models.},
  language  = {en}
}
@article{GlanderDoellner2009,
  author    = {Glander, Tassilo and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Abstract representations for interactive visualization of virtual 3D city models},
  issn      = {0198-9715},
  doi       = {10.1016/j.compenvurbsys.2009.07.003},
  year      = {2009},
  abstract  = {Virtual 3D city models increasingly cover whole city areas; hence, the perception of complex urban structures becomes increasingly difficult. Using abstract visualization, complexity of these models can be hidden where its visibility is unnecessary, while important features are maintained and highlighted for better comprehension and communication. We present a technique to automatically generalize a given virtual 3D city model consisting of building models, an infrastructure network and optional land coverage data; this technique creates several representations of increasing levels of abstraction. Using the infrastructure network, our technique groups building models and replaces them with cell blocks, while preserving local landmarks. By computing a landmark hierarchy, we reduce the set of initial landmarks in a spatially balanced manner for use in higher levels of abstraction. In four application examples, we demonstrate smooth visualization of transitions between precomputed representations; dynamic landmark highlighting according to virtual camera distance; an implementation of a cognitively enhanced route representation, and generalization lenses to combine precomputed representations in focus + context visualization.},
  language  = {en}
}
@article{IsailovićStojanovicTrappetal.2020,
  author    = {Isailović, Dušan and Stojanovic, Vladeta and Trapp, Matthias and Richter, Rico and Hajdin, Rade and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Bridge damage},
  series = {Automation in construction : an international research journal},
  volume    = {112},
  journal   = {Automation in construction : an international research journal},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0926-5805},
  doi       = {10.1016/j.autcon.2020.103088},
  pages     = {22},
  year      = {2020},
  abstract  = {Building Information Modeling (BIM) representations of bridges enriched by inspection data will add tremendous value to future Bridge Management Systems (BMSs). This paper presents an approach for point cloud-based detection of spalling damage, as well as integrating damage components into a BIM via semantic enrichment of an as-built Industry Foundation Classes (IFC) model. An approach for generating the as-built BIM, geometric reconstruction of detected damage point clusters and semantic-enrichment of the corresponding IFC model is presented. Multiview-classification is used and evaluated for the detection of spalling damage features. The semantic enrichment of as-built IFC models is based on injecting classified and reconstructed damage clusters back into the as-built IFC, thus generating an accurate as-is IFC model compliant to the BMS inspection requirements.},
  language  = {en}
}
@article{NienhausDoellner2005,
  author    = {Nienhaus, Marc and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Depicting dynamics using principles of visual art and narration's},
  issn      = {0272-1716},
  year      = {2005},
  language  = {en}
}
@article{ParedesAmorBooetal.2016,
  author    = {Paredes, E. G. and Amor, M. and Boo, M. and Bruguera, J. D. and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Hybrid terrain rendering based on the external edge primitive},
  series = {International journal of geographical information science},
  volume    = {30},
  journal   = {International journal of geographical information science},
  publisher = {American Chemical Society},
  address   = {Abingdon},
  issn      = {1365-8816},
  doi       = {10.1080/13658816.2015.1105375},
  pages     = {1095 -- 1116},
  year      = {2016},
  abstract  = {Hybrid terrain models combine large regular data sets and high-resolution irregular meshes [triangulated irregular network (TIN)] for topographically and morphologically complex terrain features such as man-made microstructures or cliffs. In this paper, a new method to generate and visualize this kind of 3D hybrid terrain models is presented. This method can integrate geographic data sets from multiple sources without a remeshing process to combine the heterogeneous data of the different models. At the same time, the original data sets are preserved without modification, and, thus, TIN meshes can be easily edited and replaced, among other features. Specifically, our approach is based on the utilization of the external edges of convexified TINs as the fundamental primitive to tessellate the space between both types of meshes. Our proposal is eminently parallel, requires only a minimal preprocessing phase, and minimizes the storage requirements when compared with the previous proposals.},
  language  = {en}
}