Hyperspektrale Fernerkundung

Hyperspektrale Fernerkundung nimmt mit der Verfügbarkeit geeigneter Sensorik auf verschiedenen Plattformen, von UAVs über Flugzeuge und Helikopter zu Satelliten, auch im militärischen Bereich stetig zu. Diese Technologie mit einer hohen spektralen und teilweise auch räumlichen Auflösung für die Bereiche Aufklärung, Identifizierung, Zielerfassung und thematische Kartographie wird demonstriert

Influence of foam morphology on flow and heat transport in a random packed bed with metallic foam pellets: an investigation using CFD

Open-cell metallic foams used as catalyst supports exhibit excellent transport properties. In this work, a unique application of metallic foam, as pelletized catalyst in a packed bed reactor, is examined. By using a wall-segment Computational Fluid Dynamics (CFD) setup, parametric analyses are carried out to investigate the influence of foam morphologies (cell size φ = 0.45 –3 mm and porosity ε = 0.55–0.95) and intrinsic conductivity on flow and heat transport characteristics in a slender packed bed (N = D/dp = 6.78) made of cylindrical metallic foam pellets. The transport processes have been modeled using an extended version of conventional particle-resolved CFD, i.e., flow and energy in inter-particle spaces are fully resolved, whereas the porous-media model is used for the effective transport processes inside highly-porous foam pellets. Simulation inputs include the processing parameters relevant to Steam Methane Reforming (SMR), analyzed for low ( Rep ∼ 100) and high ( Rep ∼ 5000) flow regimes. The effect of foam morphologies on packed beds has shown that the desired requirements contradict each other, i.e., an increase in cell size and porosity favors the reduction in pressure drop, but, it reduces the heat transfer efficiency. A design study is also conducted to find the optimum foam morphology of a cylindrical foam pellet at a higher Rep ∼ 5000, which yields φ = 0.45, ε = 0.8. Suitable correlations to predict the friction factor and the overall heat transfer coefficient in a foam-packed bed have been presented, which consider the effect of different foam morphologies over a range of particle Reynolds number, 100 ≤ Rep ≤ 5000

FASA Fire Airborne Spectral Analysis of natural disasters

At present the authors are developing the system FASA, an airborne combination of a Fourier Transform Spectrometer and an imaging system. The aim is to provide a system that is usable to investigate and monitor emissions from natural disasters such as wild fires and from volcanoes. Besides temperatures and (burned) areas FASA will also provide concentration profiles of the gaseous combustion products. These data are needed to improve the knowledge of the effects of such emissions on the global ecosystem. The paper presents a description of the instrumentation, the data evaluation procedure and shows first results of retrieval calculations based on simulated spectra

FASA - Fire Airborne Spectral Analysis of Natural Disasters

At present the authors are developing the system FASA, an airborne combination of a Fourier Transform Spectrometer and an imaging system. The aim is to provide a system that is usable to investigate and monitor emissions from natural disasters such as wild fires and from volcanoes. Besides temperatures and (burned) areas FASA will also provide concentration profiles of the gaseous combustion products. These data are needed to improve the knowledge of the effects of such emissions on the global ecosystem. The paper presents a description of the instrumentation, the data evaluation procedure and shows first results of retrieval calculations based on simulated spectra

Measurement of Mixed Biomass Burning and Mineral Dust Aerosol in the Thermal Infrared

From January 19th to February 7th, 2008, we installed a Fourier transform infrared spectrometer (FTIR) at Praia Airport on the island of Santiago, Cape Verde. Our goal was to measure the combined radiative effect of biomass burning aerosol and mineral dust usually observed there during that time of the year, when mineral dust emerging from the Sahara mixes with biomass burning aerosol transported north-westwards from the Sahelian region. Our measurements were part of the emph{Sa}haran emph{M}ineral Demph{u}st Experiemph{m}ent 2 (SAMUM 2) funded by the German Research Foundation (DFG) as continuation of the SAMUM field experiment in Morocco in 2006. SAMUM 2 is a joint venture of several German research institutes and universities and included both ground based as well as airborne measurements with the DLR Falcon research aircraft. The ground based instrumentation included spectrometers for visible and thermal infrared downwelling radiation, sun photometers, LIDAR and particle impactors while the Falcon was equipped with LIDAR and several instruments for aerosol analysis and sample return. A comparison of the FTIR measurements with radiative transfer simulations yields the expected aerosol forcing in the atmospheric window region after application of a suitable calibration method

Infrarotsignaturbewertung von agilen und hoch gepfeilten Flugzeugkonfigurationen

Das DLR betreibt seit vielen Jahren Modelle zur Bewertung der Infrarot (IR)-Signatur von Flugzeugen. Für die Simulation der IR-Signatur agiler, eventuell unbemannter Flugzeuge wurde mit den hier durchgeführten Ar-beiten das neue IR-Modell MIRA (Model for Infrared Scene Analysis) entwickelt. Es trägt den höheren Anfor-derungen bei der Signaturberechnung hoch getarnter Konfigurationen Rechnung. MIRA ermöglicht die Mo-dellierung beliebig geformter Abgasstrahlen, die durch die typischerweise rechteckigen Gasauslässe entste-hen. Zudem werden Mehrfach-Reflexionen sowohl auf der Flugzeugoberfläche als auch im Einlauf und im Abgassystem unter Berücksichtigung der bidirektionalen Reflektanzverteilungsfunktion (BRDF) bestimmt. Darüber hinaus enthalten die MIRA-Ergebnisse auch die Einflüsse der Atmosphäre und der vom Boden emit-tierten IR-Strahlung. Da der Abgasstrahl je nach Konfiguration auch von der Strömung um das Flugzeug beeinflusst werden kann, wurde MIRA mit dem DLR TAU Code gekoppelt. Bei diesem handelt es sich um ein Strömungsmodell, mit dem sowohl die Flugzeug-Umströmung als auch deren Mischung mit dem Abgasstrahl berechnet werden kann. Dieser Beitrag gibt einen Überblick über die Funktion sowie die aktuellen Fähigkei-ten des entwickelten IR-Signaturmodells MIRA. Die Verwendung der gekoppelten Modelle MIRA und TAU im Entwurfsprozess wird anhand der Optimierung des Abgassystems eines unbemannten Flugzeugs demons-triert