ARGOS - Near Real Time Airborne Monitoring System for Disaster and Traffic Applications

Kurzfassung

Near real time monitoring of natural disasters, mass events, and large traffic disasters with airborne optical sensors is a focus of research and development at the German Aerospace Center (DLR). For this purpose, a new airborne camera system was developed named 3K camera system (3K = “3Kopf-Kamera”). Image data are processed onboard on five onboard processing units using data from a real time GPS/IMU system. Processed data are sent to ground via two types of datalinks, a commercial microwave operating in the S-band. This system is called ARGOS. The data received by the ground antenna are further processed and distributed directly to the ground forces and to different institutions like the ZKI (Center for Satellite Based Crisis Information) and the DELPHI traffic portal of DLR. The time span between acquisition and reception at the end user is about 5 minutes. Main focus in the current development is the traffic processor, which extracts traffic information like traffic density and vehicle velocity from 3K image sequences. The information from a road database is used for the road and vehicle detection in the georeferenced images. Another application is the thematic mapping of natural disasters like floods, land slides, and damages after earth quakes. The requirements of civil security and rescue forces for a near real time airborne monitoring system were integrated in the first prototype system, which should be ready in the middle of 2009. National cooperation partners are the Federal Office of Civil Protection and Disaster Assistance (BBK) and the Federal Agency for Technical Relief (THW) supplemented by different regional civil security institutions in the two demonstration regions Cologne and Munich. The future plan is to operate a quickly reacting mobile ground station and an airplane on standby for monitoring of natural disasters and mass events. One important part of the ARGOS system is the 3K camera system, which consists of three non-metric off-the-shelf cameras (Canon EOS 1Ds Mark II, 16 MPixel each). The cameras are aligned in an array with one camera looking in nadir direction and two in oblique direction, which leads to an increased FOV of max 110°/31° in across track/flight direction. The pixel size and swath width are depending on the flight altitude and range between 15 cm to 50 cm and 2.5 km to 8 km respectively. This camera system can be operated in different mapping or traffic acquisition modes and thus a high resolution, colour and wide-area monitoring task even at low flight altitudes, e.g. below the clouds, is feasible. Within two minutes an area of approximately 10 km x 8 km can be monitored. The frame sensor system is coupled with a real time GPS/IMU navigation system, which enables the direct georeferencing. The ability to acquire image sequences with up to 3Hz broadens the spectrum of possible applications in particular to traffic monitoring. In this paper the relevant parts of the overall system and selected system processes are addressed and described in more detail. The experiences made in the flight campaigns of the last years are summarized with focus on the image processing part, e.g. reached accuracies of georeferencing and status of the traffic processors.