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AN AUGMENTED REALITY SYSTEM FOR EARTHQUAKE DISASTER RESPONSE
Johannes Leebmann
Institut für Photogrammetrie und Fernerkundung,
Universität Karlsruhe (TH), Englerstrasse 7, 76128 Karlsruhe, Germany — leebmann@ipf.uni-karlsruhe.de
TS ThS 19 Urban Modelling, Visualisation and Tracking
KEY WORDS: Disaster, Earthquakes, Decision Support, LIDAR, Calibration, Tracking, Virtual Reality
ABSTRACT
The paper describes the augmented reality system (ARS) developed as part of a disaster management tool of the Collaborative
Research Centre 461 (CRC461) at the Universität Karlsruhe (TH). An ARS superposes an image of reality with a virtual image that
extends the visible scenery of reality. Its use in the context of disaster management is to represent different invisible disaster-relevant
information (humans hidden by debris, simulations of damages and measures) and overlay it with the image of reality. The design of
such a system is a challenge in many ways, since the system integrates different methods like mapping, photogrammetry, inertial
navigation and differential GPS. The paper introduces into the problems of earthquake disaster response and motivates the use of an
ARS. It describes the used hardware components and discusses the data available and necessary for the system to be operational
under real conditions. The main methods required to construct and use the system are explained. The achieved results are given and
examined. Finally, some conclusions are drawn and suggestions for future work are given.
1. INTRODUCTION
The aim of an augmented reality system (ARS) is to
superimpose a real-world scenery with a virtual extended
version of itself in real time. While first works in the field of
AR reach back to Sutherland (1968) first outdoor applications
appeared quite late in literature (Feiner, 1997). The driving
forces for the new possibilities have been on the one hand the
development of the method of real time kinematic GPS and on
the other hand the improvement and miniaturisation of
orientation sensors. Several applications for outdoor augmented
reality systems have been presented in recent years. In these
studies, outdoor ARS is used for guiding visitors of a university
campus (Feiner, 1997), explaining city planning (Piekarski et
al., 2003) or guiding tourist through archeological sites (Dahne
et al., 2003).
The following work wants to encourage the use of an ARS in
the field of disaster management. The target group of this ARS
are experts for Search and Rescue (SAR). The ARS is
developed as a specialised equipment for supporting the
rescuers that try to find people trapped in the rubble of
collapsed buildings. The ARS is a part of a disaster
management tool (DMT) of the Collaborate Research Centre
461 (CRC461) at the Universität Karlsruhe (TH). The disaster
management tool is an experimental environment in which new
methods for disaster prevention and reaction planning can be
tested. In this context, the ARS component provides a most
detailed view of the planning information. It represents different
invisible disaster relevant information and overlays it with the
reality in the same scale.
The ARS is particularly suited to communicate knowledge of
experts of different fields that have to work together. Such a
situation is described by Hirschberger et al. (2001) for SAR.
The example illustrates the problems that occur during SAR
activities: The authors describe the efforts of the fire brigades to
rescue those trapped in a collapsed building. They report that
even while there were SAR experts present they could not
remove the debris themselves but needed hydraulic excavators.
But, to conduct these excavators special personnel was
necessary. The conductors of the excavators in contrary did not
909
have the knowledge of how to remove the fragments best. Care
has to be taken that fragments of the ceiling do not break and
the remaining cavities are not destroyed. This technical
knowledge has to be made comprehensible. Further more one
has to communicate how to avoid fine-grained material trickling
down to cavities underneath.
The situation shows that means are needed to easily
communicate knowledge between experts and other personnel.
In the mentioned case, the superposition of instructions and
reality could help to guide the operations. The presented
scenario is an application of an ARS directly after an
earthquake, for the so-called disaster reaction phase. It should
be mentioned, that an ARS might be applied in other phases of
the disaster cycle as explained by the UNO (2004): disaster
impact, relief, rehabilitation, reconstruction, mitigation and
preparedness. In the preparing phase before an event the helpers
could be trained with simulated damage situations displayed by
an ARS. Another important measure to get prepared for a
possible event is to establish consciousness in the population
for the risks they are living with. Simulated damages
superposed with reality could be a tool to show these risks. By
doing this, it could improve the readiness to spend money for
preparedness measures e.g. to strengthen the buildings and in
that way to reduce the number of victims.
2. HARDWARE COMPONENTS
In principle, a mobile ARS consists of devices for measuring
position and orientation, computing the virtual scene,
displaying the combined result and, eventually, a digital video
camera to capture the images of the reality.
For position tracking differential GPS is used. Real time
kinematic differential GPS involves the co-operation of two
GPS receivers. One receiver is stationary, another moving. The
stationary receiver is positioned at a known location. The
moving receiver (rover) collects the measurements needed to
calculate the current position. The accuracy of the calculated
position is improved by correction data computed by the
stationary receiver. In the case of real time kinematic GPS the
correction data has to be sent to the rover continuously to
