Visualization Based on Geographic Information in Augmented Reality

This chapter is a study on the visualization techniques of geographic information in an augmented reality environment, focusing on its user interface. Augmented reality is a technology that superimposes information over a real scene, enhancing the real world with the scene-linked information. The information is overlaid onto the real scene, dynamically based on the user’s viewpoint. When mixed reality is defined as a continuum of environments spread between reality and virtuality (Milgram et al., 1994), augmented reality is ranked within a certain range along the reality-virtuality continuum. An augmented reality environment has the following characteristics: 1) It combines real and virtual worlds; 2) It is interactive in real-time; and 3) Virtual objects are spatially registered in three dimensional (3D) spaces (Azuma, 1997). In this chapter, however, the term “augmented reality” is used as a 3D user interface that provides a user with an interactive environment. Moreover, a desktop monitor is included as a part of the interactive tabletop environment for presenting the visual scene captured by a video camera, though a head-mounted display (HMD) has typically been used as a display device. Comparison of the user’s experiences between the HMD and the licquid crystal display (LCD) monitor showed that the LCD was easier to use than the HMD under the certain conditions (Asai & Kobayashi, 2007). It was because visual instability was caused by unstable images captured by a camera attached to the HMD. The coordinate system between workspace and visual feedback is then inconsistent in the environment using a desktop monitor, which requires user’s mental transformation. In terms of interaction techniques, on the other hand, this tabletop environment gives us great merits of visual stability and tangible interaction with information or virtual objects. There have been various visualization applications based on geographic information using the augmented reality technology. Our aim is here to introduce the basic concept of geographic information visualization using augmented reality, report an example with our lunar surface browsing tools, and show the features of the user interface in the geographic information visualization using map-based augmented reality. First, the basic concept of geographic information visualization system is introduced by briefly describing general technology and its relevant applications of augmented reality. The geographic information visualization using augmented reality is mainly categorized into two styles: visualizing navigation information using GIS (geographic information system) in the real world and visualizing geographically embedded information using a real map on