A Survey of Augmented Reality

Ronald T. Azuma (1997)

This is a really interesting article about augmented reality (AR) and its potential for a wide variety of areas. The author starts by defining what is AR and what is the main difference with a similar technology called virtual reality (VR). AR consists in merging together reality and virtuality. For example, you can use a visor for watching a real table but over the table there can be different objects (say a bottle) that are laid over (superimposed) in the real image of the table. VR, on the other hand, consists in creating an entire virtual environment, completely separated from "the real world". The author explains that AR has a wide variety of potential applications within many different areas such as medicine, manufacturing, visualization and planning, entertainment and militar as well as civil aviation.

For instance, regarding medicine, a surgeon could use a visor that aids him to know exactly where to make an incision. In aviation, a pilot could use a special visor to have visual aid in order to be able to easily locate the runway during landing in low visibility conditions. In entertainment and education, a person could use special glasses to walk around ancient ruins, say Foro Romano in Rome, and he could see a virtual recreation in 3D of how the original buildings looked like superimposed exactly where the real ruins are.

The author comments on the main difficulties that AR technology has to deal with in order to be an effective tool. Making a perfect match between the real world and the virtual images being superimposed is by far the biggest challenge. The author explains that it requires an extraordinary level of precision of less than a degree. Therefore, the visor or glasses used (or whichever kind of device being used) must make use of many different internal sensors and receivers such as GPS, accelerometers, gyroscopes and even some high precision laser guidance system in order to make the virtual images match the real world as good as possible. However, the author explains that even with these advanced sensoring technologies the experience shows that making a totally exact match between reality and virtuality could take several more years of development. Nevertheless, the author emphasizes that AR could utterly change the way we work and entertain ourselves and that it could make many types of jobs and activities much safer than they are today.