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 num-bers 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 mid- and long wave infrared (MWIR and LWIR) cam-eras to detect, monitor and quantify high temperature events (HTE) like forest fires. Ground-based, 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 In-stitute for Material Research and Testing (BAM), parallel several large forest fires in Bran-denburg (Lieberose) and Mecklenburg-Vorpommern (Lübtheen) developed. In coordination with the crisis management group (local authorities, firefighters, armed forces, federal po-lice) 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 infor-mation about the fires within one data set, a broad calibration range for the LWIR camera was commanded. Using synchronized position- and 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 re-gions of adjacent flight lines. Data exchange and use of the data proved to be difficult due to limited data rates and IT in-frastructure 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 us-ing a live data link and to optimize the coordination with the control center. Further activi-ties will be coordinated by the Helmholtz Innovation Lab OPTSAL (Optische Technologien für Situationserfassung im Sicherheitsbereich), which was started at DLR in 2020. In OPTSAL hard- and software solutions are developed and activities concerning situational awareness for safety and security are coordinated with industry and authorities

Detection of Land Surface Temperature anomalies using ECOSTRESS in Olkaria geothermal field

Geothermal systems can be used to produce low-emission energy throughout the day and night, regardless of the weather conditions. These features make geothermal systems a sustainable and reliable energy source, which can be exploited on a much larger scale than it is now. Remote sensing techniques can support detecting areas potentially suitable for geothermal energy production, thereby reducing the costs of preliminary exploration. The Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) can provide nighttime thermal imagery, which can be used for geothermal anomaly detection. This paper presents a method for automated detection of geothermal anomalies using nighttime ECOSTRESS data of the study area in Olkaria, Kenya. The proposed detection method is a kernel-based one, and includes adaptions of kernel size for the cases of large geothermal anomalies. The accuracy of the method is verified with reference data acquired during field work. A producer’s accuracy of 82% is achieved, which is on average 56% points better than in randomised anomaly maps. The possible sources of errors in detection are heat capacity of surfaces, terrain features and vegetation masking the thermal signatures. The high producer’s accuracy proves potential for application in global mapping of geothermal anomalies

Parametrisation of Gas Flares Using FireBIRD Infrared Satellite Imagery

Bei der Förderung von Erdöl wird auch Erdgas gefördert, das oft abgefackelt wird. Das Abfackeln von Erdgas ist sehr schädlich für die Umwelt und die Bewohner einer Umgebung in der Gas abgefackelt wird. Demzufolge ist die Reduktion dieses Prozesses eine wichtige Aufgabe, die durch Monitoring von Gasfackeln unterstützt werden kann. Dies gelingt am besten durch Fernerkundung mit Satellitendaten. Die vorliegende Dissertation widmet sich der Parametrisierung von Gasfackeln anhand von Infrarot-Satellitenaufnahmen. Eine Gruppe von Sensoren wurde verglichen, woraus optimale Eigenschaften eines Sensors zur Gasfackelanalyse abgeleitet wurden. Danach wurde ein Modell zur Berechnung des Gasflusses aus Infrarot-Satellitenaufnahmen entwickelt. Das vorgeschlagene Modell basiert auf der Physik der Verbrennung und wird von Teilmodellen zur Berechnung der Verbrennungsparameter unterstütz. Dadurch werden Prozesse mitberücksichtigt, die bisher in der Gasfackelforschung wenig adressiert wurden. Eine Experimentenreihe erlaubte eine Charakterisierung der Flamme in Bezug auf sich verändernde Bedingungen, z.B. Gasfluss. Zusätzlich wurde das Modell durch die Experimente validiert. Die abgeleitete Genauigkeit der Gasflusswerte ist verhältnismäßig hoch, insbesondere wenn man die Komplexität und Variabilität einer Gasflamme berücksichtigt. Durch Analysieren des Sensordesigns des BIROS Sensors aus der FireBIRD-Mission des Deutschen Zentrums für Luft- und Raumfahrt konnten die Sensorparameter charakterisiert und deren Einfluss auf ein abgeleitetes Bildprodukt quantifiziert werden. Die Fähigkeit des Modells mit unterschiedlichen Sensordaten zu funktionieren, wurde geprüft durch einen Vergleich der geschätzten Gasflusswerte aus Daten von zwei Satellitensensoren. Die verglichenen Gasflusswerte sind sehr ähnlich, was die Fähigkeit des Models mit unterschiedlichen Daten gut zu funktionieren, bestätigt. Das vorgeschlagene Model hat Potenzial, das globale Monitoring von Gasfackeln zu verbessern.Routine gas flaring is harmful to the environment and people living in the vicinity of gas flares. Therefore, the reduction of this process is an important task, which can be supported by monitoring of gas flares, which can be done with remote sensing techniques. The presented work is devoted to the monitoring of gas flaring. The first aspect of the analysis was to compare a group of sensors with respect to the features crucial for gas flaring analysis. A set of requirements for an optimal sensor for this purpose was proposed. Next, a model for calculating gas flow from infrared satellite imagery was proposed, which relies on several other models, allowing to derive the values of the combustion parameters. By modelling these parameters in a gas flare, processes are accounted for that were scarcely addressed in the research conducted on gas flaring until now. To describe the characteristics of the flame coming from combustion in a flare, an experimental series was designed and conducted. The experimental series allowed to characterise the flame with respect to changing conditions, e.g. gas flow. Thus, the characteristics derived from the experiments could be included in the model for gas flow calculation. Additionally, the experiments served as a mean to validate the model. The accuracy of the derived gas flow values is relatively high, especially considering the variability of a gas flare flame. One design goal of the model for gas flow calculation was to ensure feasibility to work with data from different sensors producing equally accurate results. By analysing the design of the BIROS sensor of the DLR, the sensor parameters could be described, and their influence on the resulting imagery could be quantified. The feasibility was verified by comparing the gas flow values calculated using data from two different satellite sensors. The results obtained are very similar. The model proposed reveals potential to improve the global monitoring of gas flaring

Feasibility study of hyperspectral line-scanning camera imagery for remote sensing purposes

Hyperspectral instruments are used to characterise (terrestrial) and planetary surfaces, oceans and the atmosphere. At present there are a number of aircraft systems and space missions. Examples are DESIS on the ISS and MERTIS as part of the planetary mission Bepi Colombo. In this work a scanning system for hyperspectral panoramas is investigated. In classical systems with spectrographs, the input aperture is a long slit whose image is distributed over a 2-D detector array so that all points along a line in the scene are scanned simultaneously. The spectral dimension is then orthogonal to the slot. Low cost hyperspectral scanners have a 2D variable spectral filter with each filter positioned perpendicular to the direction of flight. The biggest challenge when using these low-cost scanners, for example for airborne applications, is the mapping of the images of the individual spectral channels to each other (co-registration). The solution to the problem is the prerequisite for using this type of hyperspectral cameras. Therefore, an investigation should focus on the process of data collection, correction and registration. To test for future applications, the camera was operated as a panorama scanner. In order to evaluate the quality, the derived results of scene classification should be described here

The Contribution of the Earth Observation to the Monitoring of Gas Flaring

Global climate changes, which can be observed in the last years, cause a challenge for the society by bringing up new risks of natural hazards and changing natural conditions. One of the important drivers for climate change is the emission of the greenhouse gases to the atmosphere, coming from e.g. industrial sites for conventional energy production, such as oil refineries. During the production of crude oil, natural gas is also being extracted as a side product. Flaring is the cheapest way to dispose of this gas. There are several alternative ways to process it, in order to avoid wasting resources and preventing atmospheric pollution, but nevertheless, they all require investments in infrastructure and are rather unprofitable. Thus, the amount of the flared gas remains high and constitutes a significant problem for the natural environment and climate. Gathering information about gas flaring, e.g. the amount of the gas burned in a specific region of interest, is a complex challenge. Quantification of gas flares in terms of greenhouse gases (GHG) emissions depends on many factors. This comprises not only technical parameter, but also the public availability of needed information. This is especially a hindering aspect in the countries, where such information is not published. Therefore, for the purpose of monitoring, an objective, independent and reliable data source is required. Satellite imagery is very well suited for this task: it can be collected almost permanently, independent of different political and economic institutions, worldwide. Monitoring and mapping of gas flaring have been first introduced to the remote sensing community by Croft in 1978. Recent development of thermal sensor systems, especially with higher spatial resolution, covering wavelengths of the electromagnetic spectrum in the longwave- (LWIR) and in the midwave-infrared (MWIR) opened new possibilities. Especially the NOAA Visible/Infrared Imager Radiometer Suite (VIIRS) and the Sentinel-3 sensor systems can provide necessary information. Nevertheless, until now, there is only one data-base, which is dedicated to collect information on gas flaring, based on VIIRS data, initiated by the World Bank. The German Aerospace Center (DLR) initiated the mission FireBIRD, in order to provide sensor systems that are specially designed for hot-spot recognition and analysis of high-temperature events. The mission consists of two small satellites TET-1 (Technologie Erprobungsträger, eng. OOV: On-Orbit Verification) and BIROS (Berlin InfraRed Optical System), both collect data in the MWIR and LWIR thermal spectrum. Higher data level products include a fire-mask; information on fire area, temperature and calculated fire radiated power (FRP). First investigations on mapping gas flare are presented. The presented study compares the existing data-base on gas flaring, analyses the features of the sensors used and gives an overview on the further needs in this field

Validierung der TET-1 Satellitensensorik

Die Freisetzung von Treibhausgasen und Aerosolen durch Brände hat einen großen Einfluss auf das globale Klima: Im Durchschnitt sind Brände für bis zu 30% der anthropogenen CO2 -Emissionen verantwortlich. Derzeit gibt es jedoch keine geeigneten Instrumente zur genauen Schätzung der Emissionsmenge und damit ihrer Auswirkungen auf das Klima. Das ist der Hintergrund dafür, dass das Deutsche Zentrum für Luft- und Raumfahrt (DLR) die FireBIRD-Konstellation gestartet hat, die im Jahr 2016 aus den beiden Satelliten TET-1 (Technology Test Platform) und dem BIROS (Bispectral Infrared Optical System) besteht. Ziel die wissenschaftliche Erforschung der damit verbundenen Fragen, sowie die frühzeitige Branddetektion aus dem Weltraum. Der Satellit - und Detektoransatz basiert auf einer bewährten DLR - Technologie, die im Rahmen der BIRD - Mission (Bispectral Infrared Detection) im Jahr 2001 realisiert wurde und vor allem für die Beobachtung von Bränden und vulkanischen Aktivitäten bis 2004 genutzt wurde

Structural and Functional RNA Motifs of SARS-CoV-2 and Influenza A Virus as a Target of Viral Inhibitors

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic, whereas the influenza A virus (IAV) causes seasonal epidemics and occasional pandemics. Both viruses lead to widespread infection and death. SARS-CoV-2 and the influenza virus are RNA viruses. The SARS-CoV-2 genome is an approximately 30 kb, positive sense, 5′ capped single-stranded RNA molecule. The influenza A virus genome possesses eight single-stranded negative-sense segments. The RNA secondary structure in the untranslated and coding regions is crucial in the viral replication cycle. The secondary structure within the RNA of SARS-CoV-2 and the influenza virus has been intensively studied. Because the whole of the SARS-CoV-2 and influenza virus replication cycles are dependent on RNA with no DNA intermediate, the RNA is a natural and promising target for the development of inhibitors. There are a lot of RNA-targeting strategies for regulating pathogenic RNA, such as small interfering RNA for RNA interference, antisense oligonucleotides, catalytic nucleic acids, and small molecules. In this review, we summarized the knowledge about the inhibition of SARS-CoV-2 and influenza A virus propagation by targeting their RNA secondary structure

Validation of the TET-1 satellite imaging sensor

The release of greenhouse gases and aerosols from �res has a large in uence on global climate: on average, �res are responsible for up to 30% of anthropogenic CO2 emissions. Currently, however, there are no suitable instruments for more precisely estimating the quantity of emissions and thus their impact on the climate. The German Aerospace Center (DLR) is contributing to the FireBIRD constellation, which will consists of the two satellite TET-1 (Technology Test Platform) launched 2012, and BIROS (Bispectral Infrared Optical System) to be launched in 2016. FireBIRD is mainly dedicated to scienti�c investigation of the issues involved as well as to early �re detection from space. The satellite and detector approach is based on proven DLR technology achieved dur- ing the BIRD (Bispectral Infrad Detection) mission, which was launched in 2001 and was primarily used for observation of �res and volcanic ac- tivity until 2004. The Payload of TET and BIROS (equal sensor system) has spectral channels in visible (VIS), near infrared (NIR), mid-wave (MIR) and a thermal infrared (TIR) channel. In the spatial domain the instrument has 5184 pixels for the VIS/NIR and 1000 pixels for the MIR/TIR channel with a Ground Sampling Distance (GSD) of about 40m (VIS/NIR) and 160m (MIR/TIR). The paper describes the satellite as well as sensor system itself and gives some results of sensor data takes form the TET Satellite. For the scienti�c use of the TET-1 and later of BIROS data it is essential to know the reached performance of the optical instruments operating in-orbit. The main part of the paper explains the validation results of the sen- sor system. The procedures and parameters includes measurements of the dark signal (DS), noise behavior and signal to noise (SNR). The ge- ometrical imaging performance will be described using the modulation transfer function (MTF). With the calculated attitude parameters a direct georeferencing is pos- sible. Deviations of spatial features from expected absolute geolocation gives an information of the accuracy of the attitude measurement system