A brief literature review follows. This is more of a topic reference for myself, than an in-depth discussion of the paper itself. 
 
RECENT ADVANCES IN AUGMENTED REALITY 
R. Azuma, Y. Baillot, R. Behringer, S. Feiner, S. Julier, B. MacIntyre 
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Azuma et.al. present an interesting survey of the state of AR technology, its recent advances, and its limitations in this paper from 2001. They provide a useful overview of topics including tracking, registration, usability, and interaction. An excellent break down of the different levels of virtual reality and augmented reality is presented as well. Various AR methods are also mentioned. These range from head worn displays to retro-reflective projection based systems. Current and potential applications for AR are also given. Some examples include military planning, simulation, navigation, factory work, construction, medical procedures, advertising, and entertainment. A brief discussion of environmental sensing is also included. This is an interesting topic, especially for unprepared environments, such as the outdoors. Indoor tracking in a prepared environment is easier but still a non-trivial task. Some techniques discussed exploit characteristics of particular locations, such as pipes and conduits running along walls and ceilings in a factory. The issue of “social acceptance” is also discussed as being a little addressed but highly influential factor in determining the future of AR among the general population.