Measuring position of a user in altering settings

Mobile services are already widespread used. It is often the first step for cell phones to become ubiquitous when they are able to submit location based information. Another application for mobile spatial aware systems is the combination of location with the computation of the head direction on a wearable computer. These Augmented Reality systems are mostly isolated applications. They offer a specific service in a specialized region, even in outdoor areas. When combining them with more widespread used localization techniques a whole of a city can be covered by a mobile service. This paper presents an approach, where several tracking techniques with different accuracies and reliability information, are offered within one system. A first implementation of this idea can be found in the research project GEIST, which allows an independent tour through a city.