Case study: Near real-time thermal mapping to support firefighting and crisis management

Hot and dry summers have led to an increase in forest fires both concerning numbers and intensity in north-eastern Germany in the last years. In the project FireSense the German Aerospace Center (DLR) has adapted its sensor system MACS (Modular Airborne Camera System) with a set of thermal midand long wave infrared (MWIR and LWIR) cameras to detect, monitor and quantify high temperature events (HTE) like forest fires. Groundbased, airborne and spaceborne measurements over fire-experiments are synchronized for cross-validation of the systems and to test the developed workflows. In summer 2019 gas flaring tests were conducted in cooperation of DLR and the Federal Institute for Material Research and Testing (BAM), parallel several large forest fires in Brandenburg (Lieberose) and Mecklenburg-Vorpommern (Lübtheen) developed. In coordination with the crisis management group (local authorities, firefighters, armed forces, federal police) to get the permits MACS conducted 3 flights over the fires in altitudes between 6000 (sunny) down to 3500 ft (under clouds), Lübtheen was covered twice, on July 2 and July 4, when the fire was already under control. Synchronously firefighting helicopters operated close to ground, also delivering videos of the fires for visual interpretation. To get both background temperatures for orientation and landscape features and also information about the fires within one data set, a broad calibration range for the LWIR camera was commanded. Using synchronized positionand orientation data of MACS with given calibration data and a Digital Terrain Model, direct geocoding and the processing of near real-time mosaics was possible using the DLR workflow even without post-processing. The accuracy was sufficient for planning purposes. Geo-tiff maps were delivered shortly after landing within less than three hours. The real-time capabilities of the system could not be used as the flights were conducted on very short notice and the radio link was not installed. The thermal data were delivered as false color heat maps. They show the thermal anomalies very well, clearly discriminating burning area, recently burnt area and unaffected forest. In the RGB data the ground fires are rarely visible as they are covered by and almost did not affect the closely standing crowns. The spread of the fires can be seen in the overlapping regions of adjacent flight lines. Data exchange and use of the data proved to be difficult due to limited data rates and IT infrastructure in the command and situation center in the field, sometimes taking more time than the acquisition and processing. This reduces the practical benefit for the data in the field. For future planned experiments for real-time mapping of forest fires this will be one of the main points to improve the latency of the data transfer to the control center ideally by using a live data link and to optimize the coordination with the control center. Further activities will be coordinated by the Helmholtz Innovation Lab OPTSAL (Optische Technologien für Situationserfassung im Sicherheitsbereich), which was started at DLR in 2020. In OPTSAL hardand software solutions are developed and activities concerning situational awareness for safety and security are coordinated with industry and authorities. 1 Deutsches Zentrum für Luftund Raumfahrt, Institut für Optische Sensorsysteme, Rutherfordstr. 2, D-12489 Berlin, E-Mail: tilman.bucher@dlr.de T. Bucher, M. Gessner, D. Hein, H. Meißner, T. Kraft, A. Soszyńska & S. Pless