Effectiveness of occluded object representations at displaying ordinal depth information in augmented reality

An experiment was conducted to investigate the utility of a number of iconographic styles in relaying ordinal depth information at vista space distances of more than 1900m. The experiment consisted of two tasks: distance judgments with respect to discrete zones, and ordinal depth determination in the presence of icon overlap. The virtual object representations were chosen based on their effectiveness, as demonstrated in previous studies. The first task is an adaptation of a previous study investigating distance judgments of occluded objects at medium field distances. We found that only one of the icon styles fared better than guessing. The second is a novel task important to situation awareness and tested two specific cases: ordinal depth of icons with 50% and 100% overlap. We found that the case of full overlap made the task effectively impossible with all icon styles, whereas in the case of partial overlap, the Ground Plane had a clear advantage.