In this paper we describe the first stand-alone Augmented Reality (AR) system with self-tracking running on an unmodified personal digital assistant (PDA) with a commercial camera. The project exploits the ready availability of consumer devices with a minimal need for infrastructure. The application provides the user with a three-dimensional augmented view of the environment. Our system achieves good overlay registration accuracy by using a popular marker-based tracking toolkit (ARToolKit), which runs directly on the PDA. We introduce an optional client/server architecture that is based on wireless networking and is able to dynamically and transparently offload the tracking task in order to provide better performance in select areas. The hardware/software framework is modular and can be easily combined with many elements of an existing AR framework. As a demonstration of the effectiveness, we present a 3D navigation application that guides a user through an unknown building to a chosen location.

We present a lightweight search function for physical objects in instrumented environments. Objects are tagged with optical markers which are scanned by a steerable camera and projector unit on the ceiling. The same projector can then highlight the objects when given the corresponding marker ID. The process is very robust regarding calibration, and no 3D model of the environment is needed. We discuss the scenario of finding books in a library or office environment and several extensions currently under development. The SUPIE environment The Saarland University Pervasive Instrumented Environment (SUPIE) is an instrumented room with various types of displays, sensors, cameras, and other devices. By means of a steerable projector, the room has continuous display capabilities which are limited in resolution and temporal availability (only one area at a time). The various other displays provide islands of higher resolution and interactivity within this display continuum. The projector can project arbitrary light

Tracking is an indispensable part of any virtual reality and augmented reality application. While the need for quality of tracking, in particular for high performance and fidelity, has led to a large body of past and current research, little attention is typically paid to software engineering aspects of tracking software. To address this issue we describe a software design and implementation that applies the pipes-and-filter architectural pattern to provide a customizable and flexible way of dealing with tracking data and configurations. The contribution of this work cumulates in the development of a generic data flow network library called OpenTracker to deal specifically with tracking data. The flexibility of the data flow network approach is demonstrated in a set of development scenarios and prototype applications in the area of mobile augmented reality. 1

In this paper we describe the port of ARToolKit onto the PocketPC platform including optimizations that led to a three-fold speedup over the native cross-compiled version. The ported ARToolKit module was successfully used in the Handheld AR project.

Handheld outdoor augmented reality requires georeferenced models of the environment to present world-registered overlays to a mobile user. We present a pipeline for managing such models that cover a wide urban area. To this aim, a geospatial database must be created, maintained and delivered to the mobile user.

Abstract. Searching books in large libraries can be a difficult task for novice library users. This paper presents SmartLibrary, a location-aware mobile library service demonstrated in the main library of the University of Oulu. The service provides map-based guidance to books and collections on a PDA. SmartLibrary is a completely software-based solution, which can be provisioned atop a WLAN installed for wireless Internet access, without any additional hardware. In a user evaluation conducted with over 30 patrons SmartLibrary was preferred over traditional shelf classification for finding books. After user evaluation the main library added SmartLibrary into their standard customer service. 1

This Editorial lead paper for the Journal of Location Based Services surveys this complex and multi-disciplinary field and identifies the key research issues. Although this field has produced early commercial disappointments, the inevitability that pervasive location-aware services on mobile devices will emerge means that much research is needed to inform these developments. The paper reviews firstly: the science and technology of positioning, geographic information science, mobile cartography, spatial cognition and interfaces, information science, ubiquitous computing; and secondly the business, content and legal, social and ethics aspects, before synthesising the key issues for this new field.

D applications, but with the focus lying on support for multi-processor and multi-pipeline systems, for distributed applications and for advanced rendering effects. Contrary to these developments, this work focusses on the expressiveness of the scene graph structure as a central tool for developing 3D user interfaces. We present the idea of a context for the traversal of a scene graph which allows to parameterize a scene graph and reuse it for different purposes. Such context sensitive scene graphs improve the inherent flexibility of a scene graph acting as a template with parameters bound during traversal. An implementation of this concept using an industry standard scene graph library is described and its use in a set of applications from the area of mobile augmented reality is demonstrated.

Environmental monitoring brings many challenges to wireless sensor networks: including the need to collect and process large volumes of data before presenting the information to the user in an easy to understand format. This paper presents SensAR, a prototype augmented reality interface specifically designed for monitoring environmental information. The input of our prototype is sound and temperature data which are located inside a networked environment. Participants can visualise 3D as well as textual representations of environmental information in real-time using a lightweight handheld computer.

Abstract — In this paper, we describe an autonomous, wearable electronic textile location awareness system that will determine a user’s location within a building given a map of that building. The system uses a moderate number of ultrasonic range transceivers as the sensing elements. Given a set of range readings from these sensors, the system attempts to match those actual readings to expected readings associated with a set of candidate locations for the wearer. These expected readings are calculated using a simulation model of the propagation of ultrasonic signals within a building. An additional algorithm is given for determining the wearer’s movement between rooms, allowing for the uncertainty associated with sensor readings in complex, multi-room environments. A wearable prototype system is described and results from this system in a variety of situations are presented. I.