AN INSIDERS VIEW OF DESERT SAND DUNES: IMMERSIVE 3-D VISUALIZATION OF AEOLIAN SEDIMENTARY STRUCTURES AND DEPOSITS USING GROUND PENETRATING RADAR DATA

Ground penetrating radar (GPR) exploits changes in permittivity within sediments to image sedimentary structures and stratigraphy and has been shown to work very well in aeolian sands. This approach has proved highly valuable in studies of aeolian sedimentary structures and has resulted in new models of dune development. When combined with high resolution optically stimulated luminescence (OSL) dating, GPR has also provided new insights into long-term (decades to millennia) dune dynamics. Full realization of the potential of GPR to determine dune evolution and dynamics is however hampered by the complexity of visualizing and quantitatively analyzing sedimentary structures and deposits in three dimensions. We report here new approaches to using GPR in a 3-D immersive visualization environment using newly developed visualization tools that will allow the user to view sedimentary structures from the inside and interactively analyze sedimentary structures and measure key properties such as thickness of units, as well as strike and dip of beds and bounding surfaces. The visualizations are being conducted using the CAVE™/FLEX™ four-sided immersive display in the Center for Advanced Visualization, Computation and Modeling (CAVCaM) at the Desert Research Institute (DRI). We started by using Vis5D, which was developed at the University of Wisconsin primarily for the interactive visualization of three-dimensional volumetric data, but have subsequently moved on to using Toirt Samhlaigh, a real-time volume renderer developed at DRI.