EnvirVis17

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https://diglib.eg.org/handle/10.2312/2631434

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Browsing EnvirVis17 by Subject "I.3.3 [Computer Graphics]"

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    An InteractiveWeb-based Doppler Wind Lidar Visualisation System
    (The Eurographics Association, 2017) Jerome, Nicholas Tan; Chilingaryan, Suren; Kopmann, Andreas; Wieser, Andreas; Karsten Rink and Ariane Middel and Dirk Zeckzer and Roxana Bujack
    With Doppler wind lidar producing significant amounts of data, providing means to extract relevant information from the data that describes atmospheric phenomena such as rain and low-level clouds is of vital importance. However, a Doppler wind lidar with a 10 Hz sampling rate produces large-scale of data at approximately ten million data items per day; therefore, introducing challenges in perceptual and interactive scalability. We present an interactive web-based visualisation system that provides summary displays of the heterogeneous lidar data. Our system applies the client-server paradigm, where our server extracts information and encodes primary lidar attributes into image's colour channels. Then, we load these encoded images and show lidar data in multiple forms at the client-side. In contrast to script-based tools such as Matlab and Ferret, our system allows researchers to begin analysing the extensive data using a more top-down methodological approach. In particular, we implemented features like zooming, multivariate filtering, and hourly variance heat map, in which GPU shaders filter data according to specific attributes. With the encoded images readily stored at the server, researchers can browse through the vast amounts of data interactively.
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    Visual Study of the Benguela Upwelling System using Pathline Predicates
    (The Eurographics Association, 2017) Nardini, Pascal; Böttinger, Michael; Scheuermann, Gerik; Schmidt, Martin; Karsten Rink and Ariane Middel and Dirk Zeckzer and Roxana Bujack
    Due to the nutrient-rich water transported to the upper layer of the ocean, coastal upwelling systems are regions especially important for marine life and fishery. In this work, we focus on a visual analysis of the spatio-temporal structure of the Benguela upwelling system using pathline predicates. Based on the 3D flow field from an ocean model simulation, we first derive space- filling trajectories covering the full model grid. From these, we select and visualize pathlines related to upwelling. In a second step, we derive a 3D scalar field representing the pathline density, which is visualized using volume rendering techniques. Further analyses of the pathlines show a distinct annual cycle in the upwelling activity, which fits well to observation-based analyses found in literature.