There is a need of technologies that could support detection and identification of elements and objects in the environment, and facilitate spatial orientation in a complex and critical situation and environments. Specifically, when it comes to navigation and orientation, there is a need to estimate depth and distances. In this research, we focused on symbols that can be used in augmented reality displays to support distance and depth estimation, in order to establish spatial orientation in different situations.
The research approach was based on the development of realistic scenarios in a virtual reality urban environment and simulating AR displays, in which participant performed depth and distance estimation tasks in different spatial configurations of buildings.
The main objectives of our research were:
· Develop and test symbols that best convey depth and distance in support of orientation.
· Define, using psychophysical methods, the behavior of symbols.
· Test the effectiveness of the symbols in conveying distance in a more cluttered urban environment, by adding a symbol to the target, while the targets were static or dynamic, and occluded or not.
Our main results indicate that people can adjust geometric parameters of a symbol (e.g. length of a line or diameter of a circle) to express the distance they estimated, and that a linear function could well fit the relations between estimated distance and adjusted parameter of the symbol.
We also discovered that when estimating distances to elements in an environment presented on a 2D display, there is a consistent underestimation of distances, as well as increasing variation in the estimations, as a function of the real distance.
We tested the effectiveness of a progressive bar and a circle as symbols, and discovered that the use of the symbol’s psychophysical functions does improve the accuracy of distance estimation. Specifically, accuracy of distance estimation improved with significant diminishing of the underestimation as a function of the distance, that accuracy was better with non-occluded targets, and specifically with a moving target.
The findings are discussed in terms of their theoretical and practical implications.