The Glass Dome: Low-Occlusion Obstacle Symbols for Conformal Displays

Abstract

Contemporary helmet mounted displays integrate high-resolution display units together with precise headtracking solutions. This combination o�ers the opportunity to show symbols in a conformal way. Conformality here means that a hazard symbol is linked to the outside scenery. Thus, a pilot intuitively understands the connection between the symbol and its corresponding terrain feature, even if the feature is not fully visible due to degraded visual conditions. To accomplish this purpose the symbol has to be su�ciently noticeable in terms of size and brightness. However, this gives rise to the danger that parts of the outside scenery are occluded by the symbol. Furthermore, symbols should not clutter the display, in order not to distract the pilot. We present a solution framework of highlighting obstacles by symbols that balance low occlusion against noticeability. Our concept allows including di�erent representations for individual classes of obstacles in a uni�ed way. We detail the implementation of the display symbols. Finally, we present results of a �rst acceptance test with pilots.