Development of an Augmented Reality Component for on the Trail Navigation in Mountainous Regions

Since the artificial interferences for civilly used GPS devices have been deactivated in 2000, navigating with GPS has become very popular. At first, automotive GPS devices were introduced to help the driver find his or her destination. Thereby, the most common application consists of the user entering his or her destination, whereupon the navigation device calculates the quickest route to reach this place according to predefined conditions. Later, the concept of using GPS for orientation was expanded onto outdoor activities. Here, however, following a preloaded track is considered as prevalent use case. Then, the smartphone allowed integrating GPS based navigation, among many other functions, into a single device. One of the functions most of all smartphones support, is a camera. The combination of camera and GPS sensor opened up the possibility of augmented reality. Thereby, the view upon the real world is supplemented with objects that are displayed as though they were part of reality. In case of a
smartphone, virtual objects are placed right onto the camera view. Thus, virtual landmarks can be shown to the user, given their geographic coordinates. In a next step, incoherently showing these landmarks could be extended by showing a whole track, consisting of connected landmarks. This would be a further contribution to facilitate outdoor orientation. In contrast to map based navigation systems, this feature would display a track onto the position where
it is actually situated. However, this way of navigation cannot stand alone, but needs to be considered as a supplement to conventional navigation. With the help of an augmented reality based navigation function, the user can compare what he or she reads on a map to what he or
she actually encounters in situ. So, he or she can re-evaluate the current situation and make decisions correspondingly. In this thesis, the feasibility of a smartphone application, providing the here described functionality, shall be demonstrated. As an additional feature, information shall be given about which parts of a track are directly visible and which are covered by a
geographic structure. Only by this means, the user knows, whether what he or she sees is part of his or her track or if it actually passes behind, e.g., a mountain. To calculate the visibility of a track, an elevation data source needs to be found. So, the approach to find an appropriate source is described in the third chapter of this thesis. Before, the requirements of an application that navigates with the help of augmented reality, are defined. To set the visibility of a track, basic knowledge about geographic calculations and spheric mathematics is needed. After describing these, the design of the finally implemented application is pointed out, and in the next chapter, its implementation is explained on the basis of source code examples. It follows a brief presentation of the application. Then, the results are analyzed concerning their compliance with the predefined requirements. Finally, an outlook is given onto improvements and possible extensions of the here presented application.