29 research outputs found

    peDOCS: Zugang zu Publikationen der Erziehungswissenschaft, Bildungsforschung und Fachdidaktik im Open Access

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    Im Beitrag wird nachgezeichnet, wie der Zugang zu Open-Access-Publikationen der Erziehungswissenschaft in Deutschland gestaltet ist. Das Besondere hierbei ist, dass die Erziehungswissenschaft über einen fachlichen Open-Access-Dokumentenserver verfügt, der in enger Kooperation mit Verlagen, Vereinen und weiteren Gruppen von Autor*innen aus der Wissenschaft getragen wird. Dieser fachspezifische Zugang unterscheidet das Repositorium von einem institutionellen und macht die Zusammenarbeit mit den verschiedenen Akteuren erst möglich.This paper describes how access to OA publications in educational science is organised in Germany. The special feature here is that educational science has a subject-specific OA document server that is supported in close cooperation with publishers, associations and other groups of authors from science. This subject-specific access distinguishes the repository from an institutional one and makes cooperation with the various actors possible in the first place

    Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO2

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    Verifying anthropogenic carbon dioxide (CO2_{2}) emissions globally is essential to inform about the progress of institutional efforts to mitigate anthropogenic climate forcing. To monitor localized emission sources, spectroscopic satellite sensors have been proposed that operate on the CO2_{2} absorption bands in the shortwave-infrared (SWIR) spectral range with ground resolution as fine as a few tens of meters to about a hundred meters. When designing such sensors, fine ground resolution requires a trade-off towards coarse spectral resolution in order to achieve sufficient noise performance. Since fine ground resolution also implies limited ground coverage, such sensors are envisioned to fly in fleets of satellites, requiring low-cost and simple design, e.g., by restricting the spectrometer to a single spectral band. Here, we use measurements of the Greenhouse Gases Observing Satellite (GOSAT) to evaluate the spectral resolution and spectral band selection of a prospective satellite sensor with fine ground resolution. To this end, we degrade GOSAT SWIR spectra of the CO2_{2} bands at 1.6 (SWIR-1) and 2.0 μm (SWIR-2) to coarse spectral resolution, without a further addition of noise, and we evaluate single-band retrievals of the column-averaged dry-air mole fractions of CO2_{2} (XCO2_{2}) by comparison to ground truth provided by the Total Carbon Column Observing Network (TCCON) and by comparison to global “native” GOSAT retrievals with native spectral resolution and spectral band selection. Coarsening spectral resolution from GOSAT’s native resolving power of > 20000 to the range of 700 to a few thousand makes the scatter of differences between the SWIR-1 and SWIR-2 retrievals and TCCON increase moderately. For resolving powers of 1200 (SWIR-1) and 1600 (SWIR-2), the scatter increases from 2.4 (native) to 3.0 ppm for SWIR-1 and 3.3 ppm for SWIR-2. Coarser spectral resolution yields only marginally worse performance than the native GOSAT configuration in terms of station-to-station variability and geophysical parameter correlations for the GOSAT–TCCON differences. Comparing the SWIR-1 and SWIR-2 configurations to native GOSAT retrievals on the global scale, however, reveals that the coarseresolution SWIR-1 and SWIR-2 configurations suffer from some spurious correlations with geophysical parameters that characterize the light-scattering properties of the scene such as particle amount, size, height and surface albedo. Overall, the SWIR-1 and SWIR-2 configurations with resolving powers of 1200 and 1600 show promising performance for future sensor design in terms of random error sources while residual errors induced by light scattering along the light path need to be investigated further. Due to the stronger CO2_{2} absorption bands in SWIR-2 than in SWIR-1, the former has the advantage that measurement noise propagates less into the retrieved XCO2_{2} and that some retrieval information on particle scattering properties is accessible

    Observational constraints on methane emissions from Polish coal mines using a ground-based remote sensing network

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    Given its abundant coal mining activities, the Upper Silesian Coal Basin (USCB) in southern Poland is one of the largest sources of anthropogenic methane (CH4_{4}) emissions in Europe. Here, we report on CH4_{4}emission estimates for coal mine ventilation facilities in the USCB. Our estimates are driven by pairwise upwind–downwind observations of the column-average dry-air mole fractions of CH4_{4} (XCH4_{4}) by a network of four portable, ground-based, sun-viewing Fourier transform spectrometers of the type EM27/SUN operated during the CoMet campaign in May–June 2018. The EM27/SUN instruments were deployed in the four cardinal directions around the USCB approximately 50 km from the center of the basin. We report on six case studies for which we inferred emissions by evaluating the mismatch between the observed downwind enhancements and simulations based on trajectory calculations releasing particles out of the ventilation shafts using the Lagrangian particle dispersion model FLEXPART. The latter was driven by wind fields calculated by WRF (Weather Research and Forecasting model) under assimilation of vertical wind profile measurements of three co-deployed wind lidars. For emission estimation, we use a Phillips–Tikhonov regularization scheme with the L-curve criterion. Diagnosed by the emissions averaging kernels, we find that, depending on the catchment area of the downwind measurements, our ad hoc network can resolve individual facilities or groups of ventilation facilities but that inspecting the emissions averaging kernels is essential to detect correlated estimates. Generally, our instantaneous emission estimates range between 80 and 133 kt CH4_{4} a1^{-1} for the southeastern part of the USCB and between 414 and 790 kt CH4_{4}a1^{-1} for various larger parts of the basin, suggesting higher emissions than expected from the annual emissions reported by the E-PRTR (European Pollutant Release and Transfer Register). Uncertainties range between 23 % and 36 %, dominated by the error contribution from uncertain wind fields

    CO2 Image: The design of an imaging spectrometer for CO2 point source quantification

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    CO2Image is a satellite demonstration mission, now in Phase B, to be launched in 2026 by the German Aerospace Center (DLR). The satellite will carry a next generation imaging spectrometer for measuring atmospheric column concentrations of Carbon Dioxide (CO2). The instrument concept reconciles compact design with fine ground resolution (50-100 m) with decent spectral resolution (1.0-1.3 nm) in the shortwave infrared spectral range (2000 nm). Thus, CO2Image will enable quantification of point source CO2 emission rates of less than 1 MtCO2/a. This will complement global monitoring missions such as CO2M, which are less sensitive to point sources due to their coarser ground resolution and hyperspectral imagers, which suffer from spectroscopic interference errors that limit the quantification

    CO2Image retrieval studies and performance analysis

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    Current and planned satellite missions such as the Japanese GOSAT (Greenhouse Gases Observing Satellite) and NASA's OCO (Orbiting Carbon Observatory) series and the upcoming Copernicus Carbon Dioxide Monitoring (CO2M) mission aim to constrain national and regional-scale emissions down to scales of urban agglomerations and large point sources. The CO2Image demonstrator mission of the German Aerospace Center (DLR) is specifically designed to detect and quantify carbon dioxide (CO2) and methane (CH4) emissions from medium-size point sources. To this end its COSIS (Carbon dioxide Sensing Imaging Spectrometer) push-broom grating spectrometer measures reflected solar radiation with a high spatial resolution of 50x50 m2, covering tiles of ~50x50 km2 extent. The instrument has a moderate spectral resolution of approximately ~1 nm and observes in a single spectral window in the 2 µm region. Here we present and discuss the impact of the expected COSIS performance on the retrieved level-2 data. The level-1 data (spectra) are generated using the Py4CAtS (Python for Computational ATmospheric Spectroscopy) line-by-line radiative transfer model and the COSIS SIMulator (COSIS-SIM). Based on the COSIS instrument parameters the analysis examines the retrieval errors related to noise which allows to estimate the detection and quantification limit of CO2 and CH4 emission rates at the instrument's spatial and spectral resolution. We further discuss the effect of heterogeneous scenes, i.e. high contrast surfaces that cause an effective distortion of the spectral response function by non-uniform illumination of the entrance slit. Finally, we assess the influence of initial guess values for the plume's vertical extent and shape on the retrieval

    The CO2Image mission: retrieval studies and performance analysis

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    The CO2Image satellite mission, led by the German Aerospace Center (DLR), aims to demonstrate the feasibility of quantifying carbon dioxide (CO2) and methane (CH4) emissions from medium-size point sources. Several DLR institutes are currently working on the reliminary design phase (Phase B) of the mission. Here we present a performance analysis based on the current instrument specifications. The Beer InfraRed Retrieval Algorithm (BIRRA), the line-by-line radiative transfer model Py4CAtS (Python for Computational ATmospheric Spectroscopy) and a COSIS (Carbon dioxide Sensing Imaging Spectrometer) instrument model are employed to infer CO2 and CH4 concentrations from synthetic COSIS spectra. We evaluate the instrument's performance and determine if it meets the intended requirements. The study assesses uncertainties in the retrieved concentrations as well as errors in point source emission estimates caused by instrument noise. First results suggest that the detection and quantification limits stated in the mission requirements document are justified. The analysis also demonstrates that retrieval errors tend to increase when the signal-to-noise ratio is low, complicating the distinction between emission sources and background concentrations. Furthermore, we discuss non-instrumental effects and demonstrate that the fit quality significantly improves if a low-level plume is scaled instead of a background reference profile that covers the atmosphere's full vertical extent. The analysis on heterogeneous scenes (high albedo contrast) reveals that the various instrument setups perform similarly for both molecules

    Ausweitung des Sojaanbaus in Deutschland durch züchterische Anpassung sowie pflanzenbauliche und verarbeitungstechnische Optimierung

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    Die Arbeiten im Sojaforschungsprojekt waren erfolgreich und konnten wichtige Impulse für die Ausweitung des Sojaanbaus in Deutschland geben. So sind die entwickelten Stämme und Kreuzungsnachkommen eine Basis für den Aufbau einer eigenständigen deutschen Sojazüchtung. Die Sorten Korus und Protibus erwiesen sich als besonders geeignet für die Tofuherstellung. Die im Projekt entwickelte Labortofurei ist ein Züchtungsinstrument zur Identifikation vielversprechender Genotypen, mit dem auch die weitere Entwicklung frühreifer Tofusojasorten unterstützt werden kann. In Gefäßversuchen konnte gezeigt werden, dass die Reaktion auf Kühlestress während der Hülsenansatzphase zwischen den Sorten variiert und es tolerante, kompensierende und sensitive Sorten gibt. Die praktische Selektion auf Kältetoleranz war erfolgreich und für die Selektion auf Unkrauttoleranz konnte ein System etabliert werden. Bis auf das Präparat Radicin können die vorhandenen kommerziellen Bradyrhizobienpräparate für den Praxiseinsatz empfohlen werden. Die Hypothese, dass die Selektion des Symbiosepartners auf Kühletoleranz lohnenswert ist, wurde bestätigt. Bei der Sortenprüfung in ganz Deutschland zeigte sich, dass die Anbauwürdigkeit von Soja gut und nur an wenigen der geprüften Standorte nicht gegeben war. Die 00-Sorte ES-Mentor lieferte insgesamt die höchsten Relativerträge sowie den höchsten Rohproteinertrag, bei den 000-Sorten schnitt Sultana besonders gut ab. Eine Variation der Saatzeit sowie verschiedene Verfrühungstechniken erweisen sich nicht als ertragsrelevant. Beim Erfolg der Unkrautregulierung mit Torsionshacke, Fingerhacke und Flachhäufler gab es keine Unterschiede. Im Dammanbau lassen sich Sojabohnen mit gutem Unkrautregulierungserfolg kultivieren. Bei der Sojaaufbereitung sollte eine unnötig hohe Erhitzung der Bohnen bei der Aufbereitung vermieden werden, da durch die Erhitzung neben der Trypsininhibitoraktivität auch Eiweißverdaulichkeit reduziert werden. Mit ausschließlich indirekter, länger einwirkender, trockener Wärme (z. B. Biogasabwärme), ist es schwierig, gute Aufbereitungsqualitäten zu erzielen. Der Wissenstransfer mit Feldtagen und Website www.sojainfo.de war wichtig und erfolgreich zur Steigerung des Interesses am heimischen Sojaanbau

    Towards spaceborne monitoring of localized CO2 emissions: an instrument concept and first performance assessment

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    This paper presents the concept of a spaceborne imaging spectrometer targeting the routine monitoring of CO2 emissions from localized point sources down to an emission strength of about 1 Mt CO2/yr. Using high-resolution CO2 emission and albedo data, it is shown that CO2 plumes from point sources with an emission strength down to the order of 0.3 Mt CO2/yr can be resolved in an urban environment (when limited by instrument noise only), hence leaving significant margin for additional errors

    Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO2

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    Verifying anthropogenic carbon dioxide (CO2) emissions globally is essential to inform about the progress of institutional efforts to mitigate anthropogenic climate forcing. To monitor localized emission sources, spectroscopic satellite sensors have been proposed that operate on the CO2 absorption bands in the shortwave-infrared (SWIR) spectral range with ground resolution as fine as a few tens of meters to about a hundred meters. When designing such sensors, fine ground resolution requires a trade-off towards coarse spectral resolution in order to achieve sufficient noise performance. Since fine ground resolution also implies limited ground coverage, such sensors are envisioned to fly in fleets of satellites, requiring low-cost and simple design, e.g., by restricting the spectrometer to a single spectral band. Here, we use measurements of the Greenhouse Gases Observing Satellite (GOSAT) to evaluate the spectral resolution and spectral band selection of a prospective satellite sensor with fine ground resolution. To this end, we degrade GOSAT SWIR spectra of the CO2 bands at 1.6 (SWIR-1) and 2.0 µm (SWIR-2) to coarse spectral resolution, without a further addition of noise, and we evaluate single-band retrievals of the column-averaged dry-air mole fractions of CO2 (XCO2) by comparison to ground truth provided by the Total Carbon Column Observing Network (TCCON) and by comparison to global native GOSAT retrievals with native spectral resolution and spectral band selection. Coarsening spectral resolution from GOSAT\u27s native resolving power of \u3e20 000 to the range of 700 to a few thousand makes the scatter of differences between the SWIR-1 and SWIR-2 retrievals and TCCON increase moderately. For resolving powers of 1200 (SWIR-1) and 1600 (SWIR-2), the scatter increases from 2.4 (native) to 3.0 ppm for SWIR-1 and 3.3 ppm for SWIR-2. Coarser spectral resolution yields only marginally worse performance than the native GOSAT configuration in terms of station-to-station variability and geophysical parameter correlations for the GOSAT-TCCON differences. Comparing the SWIR-1 and SWIR-2 configurations to native GOSAT retrievals on the global scale, however, reveals that the coarse-resolution SWIR-1 and SWIR-2 configurations suffer from some spurious correlations with geophysical parameters that characterize the light-scattering properties of the scene such as particle amount, size, height and surface albedo. Overall, the SWIR-1 and SWIR-2 configurations with resolving powers of 1200 and 1600 show promising performance for future sensor design in terms of random error sources while residual errors induced by light scattering along the light path need to be investigated further. Due to the stronger CO2 absorption bands in SWIR-2 than in SWIR-1, the former has the advantage that measurement noise propagates less into the retrieved XCO2 and that some retrieval information on particle scattering properties is accessible
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