Web-based 4D visualization of marine geo-data using WebGL

For marine logistics and maintenance of extensive and expensive marine engineering projects in the coastal zone, it is essential that institutions provide the public with relevant information in an easily understandable yet comprehensive manner over the web. A perennial challenge, however, has been the development of spatio-temporal (four-dimensional (4D)) geo-visualization algorithms to enable the integration of time-varying geo-information in map-based visualizations on the Internet. In this paper, we address the challenge of visualizing marine spatial data in web-based applications through a 4D visualization concept, focusing on usability criteria, performance parameters, the required implementation effort, and delivering a breath of spatial information that supports decision-making on multiple levels. We used Web Graphic Library (WebGL) to validate our concept through a prototypical implementation. In our technology evaluation, WebGL proved highly suitable for the development of interactive, responsive, efficient, and mobile web-based Geographic Information applications, including 2D, 3D, and 4D (spatiotemporal) content. During our research, we identified a number of open research questions, including mapping graphic variables to thematic expressivity, representation of the time dimension in 4D systems, generic temporal generalization, and integration of (pseudo-)photorealistic illustrations in web-based geo-visualization systems.