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Modern 3D geovisualization systems (3DGeoVSs) are complex and evolving systems that are required to be adaptable and leverage distributed resources, including massive geodata. This article focuses on 3DGeoVSs built based on the principles of service-oriented architectures, standards and image-based representations (SSI) to address practically relevant challenges and potentials. Such systems facilitate resource sharing and agile and efficient system construction and change in an interoperable manner, while exploiting images as efficient, decoupled and interoperable representations. The software architecture of a 3DGeoVS and its underlying visualization model have strong effects on the system's quality attributes and support various system life cycle activities. This article contributes a software reference architecture (SRA) for 3DGeoVSs based on SSI that can be used to design, describe and analyze concrete software architectures with the intended primary benefit of an increase in effectiveness and efficiency in such activities. The SRA integrates existing, proven technology and novel contributions in a unique manner. As the foundation for the SRA, we propose the generalized visualization pipeline model that generalizes and overcomes expressiveness limitations of the prevalent visualization pipeline model. To facilitate exploiting image-based representations (IReps), the SRA integrates approaches for the representation, provisioning and styling of and interaction with IReps. Five applications of the SRA provide proofs of concept for the general applicability and utility of the SRA. A qualitative evaluation indicates the overall suitability of the SRA, its applications and the general approach of building 3DGeoVSs based on SSI., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe; 1131

Lead sediment contamination in Lake Erie stems from a long history of natural and synthetic resource production. Sediment samples with variable sampling densities were collected by the Canada Centre for Inland Waters in 1971, 1997/1998, and 2014. The kriging interpolation method was used to create continuous sediment contamination surfaces for time/space comparisons. Change detection analyses identified an overall decreasing trend in high lead pollution levels from 1971 to 2014, while sediments with the lowest concentrations increased in surface area. Lake-wide circulation patterns and bathymetric data were added to interpolated contamination surfaces to enhance the understanding of interrelated hydrodynamic processes and geophysical features in the movement of contaminated sediments. Utilizing visualization tools in Esri’s ArcScene, bathymetric data were employed to enhance the geographic context of contamination maps. The physical barriers to sediment transportation created by bathymetric features can be visualized in three-dimensions. Elevated features between lake basins are easily recognized as impedances to lake currents when circulation directions are draped over the bathymetric model. By using illumination tools and techniques, geovisualizations of lead sediment contamination throughout Lake Erie create a scientific communication tool for a wide audience to use in multiple-criteria decision making for environmental remediation of sediment contamination.

The purpose of this paper was to study the influence of cartographic scale and flight design on data acquisition using unmanned aerial systems (UASs) to create augmented reality 3D geovisualization of geosites. The relationship between geographical and cartographic scales, the spatial resolution of UAS-acquired images, along with their relationship with the produced 3D models of geosites, were investigated. Additionally, the lighting of the produced 3D models was examined as a key visual variable in the 3D space. Furthermore, the adaptation of the 360° panoramas as environmental lighting parameters was considered. The geosite selected as a case study was the gorge of the river Voulgaris in the western part of the island of Lesvos, which is located in the northeastern part of the Aegean Sea in Greece. The methodology applied consisted of four pillars: (i) scale-variant flight planning, (ii) data acquisition, (iii) data processing, (iv) AR, 3D geovisualization. Based on the geographic and cartographic scales, the flight design calculates the most appropriate flight parameters (height, speed, and image overlaps) to achieve the desired spatial resolution (3 cm) capable of illustrating all the scale-variant details of the geosite when mapped in 3D. High-resolution oblique aerial images and 360° panoramic aerial images were acquired using scale-variant flight plans. The data were processed using image processing algorithms to produce 3D models and create mosaic panoramas. The 3D geovisualization of the geosite selected was created using the textured 3D model produced from the aerial images. The panoramic images were converted to high-dynamic-range image (HDRI) panoramas and used as a background to the 3D model. The geovisualization was transferred and displayed in the virtual space where the panoramas were used as a light source, thus enlightening the model. Data acquisition and flight planning were crucial scale-variant steps in the 3D geovisualization. These two processes comprised the most important factors in 3D geovisualization creation embedded in the virtual space as they designated the geometry of the 3D model. The use of panoramas as the illumination parameter of an outdoor 3D scene of a geosite contributed significantly to its photorealistic performance into the 3D augmented reality and virtual space.

Augmented reality (AR), in conjunction with 3D geovisualization methods, can provide significant support in monitoring geoconservation activities in protected geosites, such as the excavation process in fossil sites. The excavation process requires a monitoring methodology that will provide a complete and accurate overview of the fossils, their dimensions, and location within the different pyroclastic horizons, and the progress of the excavation works. The main purpose of this paper is the development of a user-friendly augmented map application, specifically designed for tracking the position of petrified tree trunks, providing information for their geometric features, and mapping the spatiotemporal changes occurring in the surrounding space. It also aims to probe whether the rapid acquisition of a 4K video can generate cartographic derivatives of petrified findings during a geosite excavation. A database accumulated 2D and 3D cartographic information, while the geovisualization environment displayed the surface alterations, at two scales: a) 1:500 (excavation area) and b) 1:50 (trench level). Unmanned aerial systems (UASs), used for data acquisition in three excavation periods, consisted of two flights at two different altitudes: one to record changes throughout the study area and the other to provide information on trunks at trench level, via a high-resolution (4K) video. Image-based 3D modeling followed, in which image georeferencing was conducted with ground control points (GCPs). Finally, 2D and 3D geovisualizations were created to depict the excavation changes through time. The cartographic products generated at two cartographic scales depicted the spatiotemporal changes of the excavation.

Last years the role of Unmanned Aerial Systems is increasing in a wide variety of scientific aspects that need fast and reliable geodata. Nowadays, the effectiveness of the quality and the resolution that the UAS provide in spatial data acquisition are fulfilling scientific standards. Thus, UAS have a prominent role in post-earthquake damage assessment as they are capable of collecting high in resolution data for mapping spatiotemporal phenomena. The implementation of very detailed 3D Geovisualization requires oblique photos of the building faces. Thus, the UAS's data acquisition of nadir photos solely, is limited as it lacks crucial information for buildings facades. In this work, a UAS multi-camera rig installation is presented for the collection and simultaneous acquisition of nadir and in three different directions oblique photos. The acquired data were used for the creation of post-earthquake building facade 3D geovisualisation of Vrisa village in Lesvos island after the Mw6.3 earthquake on June 12, 2017 at two different spatial scales. The results showed that the use of a multi-camera rig attached to UAS can produce 3D visualizations capable of depicting in detail the diversity and the small size of cracks in roofs or facades of the post-earthquake buildings. Thus, the produced geovisualizations are a valuable tool for measurements of area and volume of house debris. Moreover, the results proved that the installation of a multi-camera rig in a UAS for data acquisition and the creation of accurate 3D visualizations using these data could be a valuable and useful tool for post-earthquake damage assessment.

Using the notion of commuting flexibility, this paper investigates the intra-personal day-to-day variability and flexibility of commuting behavior using a 7-day GPS dataset collected in Beijing, China. Four dimensions of commuting variability are evaluated: space, time, travel mode, and travel route. The results indicate that the commute trip is flexible and complex in a variety of ways. Through 3D geovisualizations we were able to identify seven distinctive commuting patterns based on different combinations of the four dimensions of commuting flexibility. The results call into question the common presupposition that the commute trip is stable and fixed in many respects. Among the four dimensions of commuting flexibility, we found that variation or flexibility in time is more common than variation in the other three dimensions of commuting flexibility. This means that temporal adjustment for coping with commute problems is likely to be the most feasible option for suburban residents in Beijing.