Augmented reality applications combine real world data and computer-generated data to create a user environment. Real world data may be collected using any suitable data collection means and processed and combined with computer-generated data to create the user environment. One of the most common approaches to augmented reality is the use of live video images captured with a camera that are processed and augmented with computer-generated graphics or other images. The resulting augmented video images are then presented to a user through a user interface, such as a video monitor. In many augmented reality applications, users interact with each other. Augmented reality can be used in video games, mapping, navigation, advertising, architecture visualization, and numerous other applications.
In order to operate and interact in an augmented reality system, a user may need location information for other users in the virtual environment created by the augmented reality application. More specifically, a user may have to determine another user's location relative to the location of that user in the virtual environment. The orientation and/or direction of movement of users may also be required to continue to maintain a common coordinate system that enables the execution of an augmented reality application. By determining and maintaining a common coordinate system, the augmented reality application can present a more realistic environment to users.