The usage of 3D models acquired from airborne and terrestrial laser scans within a web-based GIS ... more The usage of 3D models acquired from airborne and terrestrial laser scans within a web-based GIS environment allows a new way to conduct archeological research but also demands new approaches and concepts in the development of infrastructure that supports such research. This article gives an overview of a design and prototypical implementation of a 4D-webgis for archaeological research. The infrastructure is based on WebGL and the three.js framework in combination with the W3DS. Initial results indicate that this is an appropriate framework for the development of a preformat 4D-webgis architecture that supports temporal visualization and analysis of archaeological data.
Archaeological projects increasingly collect airborne LiDAR data to use as a remote sensing tool ... more Archaeological projects increasingly collect airborne LiDAR data to use as a remote sensing tool for survey and analysis. Publication possibilities for LiDAR datasets, however, are limited due to the large size and often proprietary nature of the data. Fortunately, web-based, geographic information systems (WebGIS) that can securely manage temporal and spatial data hold great promise as virtual research environments for working with and publishing LiDAR data. To test this and to obtain new data for archaeological research, in 2013, the MayaArch3D Project (www.mayaarch3d.org) collected LiDAR data for the archaeological site of Copan, Honduras. Results include: 1) more accurate archaeological maps, 2) identification of unrecorded archaeological features, 3) an assessment of combining LiDAR and ground-checking to increase data accuracy in ecologically and topographically diverse landscapes, and 4) new LiDAR datasets that are hosted in a 3D WebGIS and integrated with other archaeological data to enhance data accessibility and collaborative research. Free link to online version of the paper good through January 4, 2016: http://www.sciencedirect.com/science/article/pii/S2352409X15301759
The MayaArch3D project aims to realize a web-based archaeological research platform bringing spat... more The MayaArch3D project aims to realize a web-based archaeological research platform bringing spatial and non-spatial databases together and providing visualization and analysis tools. Especially the 3D components of the platform use hierarchical segmentation concepts to structure the data and to perform queries on semantic entities.
The following paper presents a technical framework that allows for visualization of spatio-tempor... more The following paper presents a technical framework that allows for visualization of spatio-temporal quality metrics (user activity, topicality or number of features) of Volunteered Geographic Information using the example of OpenStreetMap (OSM). The aim of the system is to allow for analyzing the spatially heterogeneous data quality of VGI by a.) providing a spatio--temporal database of indicators derived from VGI that can be used in more complex statistical analysis and data mining of the data and b.) to provide a web--based visualization for first visual analysis of the data. The framework is based on a database applying a star schema separating geo-spatial and temporal information from attribute values. Further, a web-based client has been implemented on top of a Web Map Service, which allows for visual exploration of the data.
Collaborative mapping projects, such as OpenStreetMap (OSM), have received tremendous amounts of ... more Collaborative mapping projects, such as OpenStreetMap (OSM), have received tremendous amounts of contributed data from voluntary participants over time. So far, most research efforts deal with data quality issues, but the OSM evolution across space and over time has not been noted. Therefore, this study is dedicated to the evolution of the contributed information in order to understand an emergent phenomenon of so-called collaborative contributing. The main objective of this paper is to monitor the evolutional pattern of OSM and predict potential future states through a cellular automata (CA) model. This is exceedingly relevant for numerous OSMbased applications. Descriptive spatiotemporal analysis of the contributions for the time period 2007-2012, using the city of Heidelberg (Germany) as a case study, reveals that early contributions are given three years after the launching of OSM, while after nearly six years, most of the areas are discovered. The simulation results for the validated CA model, predicting OSM states for 2014, provide clear evidence that most of the areas have been explored three years after people began mapping until 2010, and thereafter, the densification process has begun and will cover most parts of the city although the amount of contribution depends on the land use types.
Techniques and Technologies in Geoinformatics, 2014
The rapidly growing number of crowdsourcing platforms generates huge volumes of volunteered geogr... more The rapidly growing number of crowdsourcing platforms generates huge volumes of volunteered geographic information (VGI), which requires analysis to reveal their potential. The huge volumes of data appear as an opportunity to improve various applications, including routing and navigation services. How existing techniques for dealing with Big Data could be useful for the analysis of VGI remains an open question, since VGI differs from traditional data. In this paper, we focus on examining the latest developments and issues associated with big data from the perspective of the analysis of VGI. This paper notably presents our new architecture for exploiting Big VGI in event service processing in support to optimization of routing service. In addition, our study highlights the opportunities that are created by the emergence of Big VGI and crowdsourced data on improving routing and navigation services, as well as the challenges that remain to be addressed to make this a reality. Finally, avenues for future research on the next generation of collaborative routing and navigation services are presented.
ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences, 2014
Many important Cultural Heritage sites have been studied over long periods of time by different m... more Many important Cultural Heritage sites have been studied over long periods of time by different means of technical equipment, methods and intentions by different researchers. This has led to huge amounts of heterogeneous "traditional" datasets and formats. The rising popularity of 3D models in the field of Cultural Heritage in recent years has brought additional data formats and makes it even more necessary to find solutions to manage, publish and study these data in an integrated way. The MayaArch3D project aims to realize such an integrative approach by establishing a web-based research platform bringing spatial and non-spatial databases together and providing visualization and analysis tools. Especially the 3D components of the platform use hierarchical segmentation concepts to structure the data and to perform queries on semantic entities. This paper presents a database schema to organize not only segmented models but also different Levels-of-Details and other representations of the same entity. It is further implemented in a spatial database which allows the storing of georeferenced 3D data. This enables organization and queries by semantic, geometric and spatial properties. As service for the delivery of the segmented models a standardization candidate of the OpenGeospatialConsortium (OGC), the Web3DService (W3DS) has been extended to cope with the new database schema and deliver a web friendly format for WebGL rendering. Finally a generic user interface is presented which uses the segments as navigation metaphor to browse and query the semantic segmentation levels and retrieve information from an external database of the German Archaeological Institute (DAI).
The usage of 3D models acquired from airborne and terrestrial laser scans within a web-based GIS ... more The usage of 3D models acquired from airborne and terrestrial laser scans within a web-based GIS environment allows a new way to conduct archeological research but also demands new approaches and concepts in the development of infrastructure that supports such research. This article gives an overview of a design and prototypical implementation of a 4D-webgis for archaeological research. The infrastructure is based on WebGL and the three.js framework in combination with the W3DS. Initial results indicate that this is an appropriate framework for the development of a preformat 4D-webgis architecture that supports temporal visualization and analysis of archaeological data.
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Papers by Lukas Loos