Visualization of Space Debris using Orbital Representation and Volume Rendering

Abstract: This report covers a master’s thesis project done at the University Of Utah for the OpenSpace project. OpenSpace is a open-source astronomy visualization software and the thesis focus was to visualize the ever-increasing number of man-made space debris. Two different visualization methods have been used in this thesis. One was a volume rendering and it was evaluated how it works in relation to an orbital trail representation, which was the other method. If the volumetric representation would reduce cluttering, is one of the aspects that will be evaluated, as well as a more open ended exploratory question which is if the volumetric representation can provide any new insights about the data. In short, will a volumetric representation give anything that an orbital representation cannot? A volume rendering can use different types of grids. The thesis evaluates the pros and cons of a cartesian- and spherical grid, as well as the different resolution of the grid and tweaks in the transfer function. An orbital trail representation was previously implemented in OpenSpace (which will be called the individual scene graph node implementation in this report) that had its pros. One con, however, was that it did not scale very well with increasing number of data elements. Visualizing all the data sets containing each trackable piece of space debris simultaneously using this implementation causes the software to slow down significantly. An alternative implementation (which will be called single draw call implementation in this report) was therefore tested in hopes to solve this issue. To see the performance difference, tests were performed where frame time for the whole scene was measured.