765 research outputs found
Inundation mapping using C- and X-band SAR data: From algorithms to fully-automated flood services
Get PDFTwele, André; Sandro, Martinis; Wenxi, Cao; Simon, Plank
German Aerospace Center (DLR), Germany
Since the establishment of the ZKI (Center for Satellite-Based Crisis Information) at the German Aerospace Center (DLR), the development of EO-based methodologies for the rapid mapping of flood situations has been of major concern. This can be especially contributed to the fact that inundations constitute the majority of all ZKI-activations as well as activations of the International Charter ‘Space and Major Disasters’.
These requirements have led to the development of dedicated SAR-based flood mapping tools which have been utilized during numerous rapid mapping activities of flood situations. The core of these tools is an automatic tile-based thresholding approach (Martinis et al. 2009, 2011, Martinis and Twele 2010) which allows separating inundated regions from land-areas without any user interaction.
Recently, the SAR-based flood detection algorithm has been substantially extended and refined in robustness and transferability to guarantee high classification accuracy under different environmental conditions and sensor configurations with the ultimate goal to allow its implementation in an automatic processing chain (Martinis et al. 2014). The processing chain including SAR data pre-processing, computation and adaption of global auxiliary data, unsupervised initialization of the classification as well as post-classification refinement by using a fuzzy logic-based approach is automatically triggered after new SAR data is available on a delivery server. The dissemination of flood maps resulting from the service is performed through a dedicated web client. With respect to accuracy and computational effort, experiments performed on a data set of >200 different TerraSAR-X scenes acquired during flooding all over the world with different sensor configurations confirmed the robustness and effectiveness of the flood mapping service.
The processing chain has recently been adapted to the new European Space Agency’s C-band SAR mission Sentinel-1. The thematic processor has further been enhanced through the integration of the “Height above nearest drainage index” (Rennó et al. 2008) which helps to reduce water look-alikes depending on the hydrologic-topographic setting. In contrast to the current TerraSAR-X based thematic service, Sentinel-1 enables a systematic disaster monitoring with high spatial and temporal resolutions. This is a major advantage since the time-consuming step of tasking new satellite data can be omitted. By minimizing the time delay between data delivery and product dissemination it is expected that the proposed service enhances the value of remote sensing during flood management activities and supports applications in hydrology, where information about the flood extent is systematically assimilated into hydrologic and hydraulic models.
The presentation will introduce to the technical concept of the SAR-based fully-automated processing chains, with a focus on the current status of the Sentinel-1 flood service.
References:
Martinis, S., Twele, A. & Voigt, S. 2009: Towards operational near real-time flood detection using a split-based automatic thresholding procedure on high resolution TerraSAR-X data. Natural Hazards and Earth System Sciences (NHESS), 9, 303-314.
Martinis, S. & Twele, A. 2010: A Hierarchical Spatio-Temporal Markov Model for Improved Flood Mapping Using Multi-Temporal X-Band SAR Data. Remote Sensing, 2 (9), 2240-2258.
46
Martinis, S., Twele, A. & Voigt, S. 2011: Unsupervised extraction of flood-induced backscatter changes in SAR data using Markov image modeling on irregular graphs. IEEE Transactions on Geoscience and Remote Sensing, 49 (1), 251-263.
Martinis, S., Twele, A. & Kersten, J. 2014 (in press): A fully automated TerraSAR-X based flood service. ISPRS Journal of Photogrammetry and Remote Sensing.
Rennó, C. D., Nobre, A. D., Cuartas, L. A., Soares, J. V., Hodnett, M. G., Tomasella, J. & Waterloo, M. J. 2008: HAND, a new terrain descriptor using SRTM-DEM: Mapping terrafirme rainforest environments in Amazonia. Remote Sensing of Environment, 112 (9), 3469-3481
The short life of the volcanic island New Late'iki (Tonga) analyzed by multi-sensor remote sensing data
Get PDFSatellite-based Earth observation plays a key role for monitoring volcanoes, especially those which are located in remote areas and which very often are not observed by a terrestrial monitoring network. In our study we jointly analyzed data from thermal (Moderate Resolution Imaging Spectrometer MODIS and Visible Infrared Imaging Radiometer Suite VIIRS), optical (Operational Land Imager and Multispectral Instrument) and synthetic aperture radar (SAR) (Sentinel-1 and TerraSAR-X) satellite sensors to investigate the mid-October 2019 surtseyan eruption at Late'ki Volcano, located on the Tonga Volcanic Arc. During the eruption, the remains of an older volcanic island formed in 1995 collapsed and a new volcanic island, called New Late'iki was formed. After the 12 days long lasting eruption, we observed a rapid change of the island's shape and size, and an erosion of this newly formed volcanic island, which was reclaimed by the ocean two months after the eruption ceased. This fast erosion of New Late'iki Island is in strong contrast to the over 25 years long survival of the volcanic island formed in 1995
Automatic oil spill detection in TerraSAR-X data using multi-contextual Markov modeling on irregular graphs
No full textThis paper describes the workflow of an automatic near-real time oil spill detection approach using single-polarized high resolution X-Band Synthetic Aperture Radar satellite data. Dark formations on the water surface are classified in a completely unsupervised way using an automatic tile-based thresholding procedure. The derived global threshold value is used for the initialization of a hybrid multi-contextual Markov image model which integrates scale-dependent and spatial contextual information on irregular hierarchical graph structures into the segment-based labeling process of slick-covered and slick-free water surfaces. Experimental investigations performed on TerraSAR-X ScanSAR data acquired during large-scale oil pollutions in the Gulf of Mexico in May 2010 confirm the effectiveness of the proposed method with respect to accuracy and computational effort
RETURN ON INVESTMENT IN CORPORATE RESPONSIBILITY: Measuring the Social, Economic, and Environmental Value of Sustainable Business
No full textIn today’s climate, companies must be economically successful and at the same time take social responsibility. Author Cesar Sandro Saenz Acosta introduces a new SROIM (Social Return on Investment Management) model, to design and measure the social value created by companies. © 2018 Emerald Publishing Limited
Ermeneutica Sociologica
Get PDFL'autore intende ancorare la sociologia al presupposto che la comprensione dell'essere umano in quanto individuo socialmente definito e costruito risiede nella socialitàThe author intends to anchor the sociology the assumption that the understanding of the human being as an individual socially defined and constructed lies in socializin
Né qui, né altrove : migration, detention, desertion : a dialogue
No full textSandro Mezzadra teaches the History of Contemporary Political Thought at the University of Bologna. He is an active figure in the alternative globalisation movement in Italy, and has been particularly involved in bringing the question of migration to the centre of political struggle in that movement. Sandro is the author of works such as Diritto di fuga: Migrazioni, cittadinanza, globalizzazione (2001) and (with Fabio Raimondi) Oltre Genova, oltre New York: Tesi sul movimento globale (2001). He is also a member of the editorial collective of DeriveApprodi magazine, one of the chief venues in Italy for the critical analysis of contemporary capitalism. We met in Bologna one foggy January afternoon to discuss the global movement, migration, and border control in Europe and Australia
The part-time work and job on call in JustEatTakeaway supplementary company agreement for Takeaway.com Express Italy (Just Eat group) riders
Get PDFThe comment deals with the part-time work regulation, contained, in particular, in Part II of the JustEatTakeaway supplementary company
agreement. The use of this instrument is expected to be massive, considering that it is, in the parties' plans, the common form of work in the company.
The author analyses the provisions contained in the collective agreement, especially in the light of the discipline contained in the CCNL Logistica, Trasporto, Merci e Spedizione and in the Protocol signed on 18 July 2018 for the same sector. The author also discusses the rules on overtime and supplementary work and the rules on intermittent work, which are also subject to specific contractual regulations
Bridging the Boundaries of Science and Technology: Author-Inventors and Quality of Inventions
No full textA growing body of research examines the relationship between science and technology by using a social network lens to look at the collaboration networks between authors and inventors. Building on this research, we study how publishing inventors’ (author-inventors’) structural position in scientific (co-authorship) and technological (co-invention) networks affects the quality of their inventions. We probe author-inventors’ characteristics by identifying those who act as cutpoints—i.e., those who play a pivotal role in holding the two networks together. Cutpoints can be connected to more or less cohesive subgroups of the scientific network and hence have access to more or less diverse knowledge bases. The results of the analysis suggest that author-inventors’ structural position—in particular, whether they are cutpoints and belong to more cohesive subgroups of the scientific network—is highly consequential for the quality of the inventions with which they are involved. We tested our hypotheses in the emerging field of nanotechnology. The theoretical and managerial implications of the results are discussed
<i>Primavera</i> / <i>The Birth of Venus</i> by Sandro Botticelli. Representations, Reinterpretations
No full textTekst pochodzi z pracy magisterskiej pt. "Primavera" i "Narodziny Wenus" Sandro Botticellego. Reinterpretacje, ekfrazy, reprezentacje (promotor: prof. dr hab. Dariusz Czaja), obronionej w IEiAKUJ w roku 2016. Poświęcony jest rozwojowi badań nad obrazem, ponownym odkryciem dzieł Botticellego w kręgach prerafaelitów oraz ich późniejszej reprezentacji w kulturze.The text is composed of an introduction and third chapter of an M.A. dissertation: “Primavera” / “The Birth of Venus” by Sandro Botticelli. Reinterpretations, Ekphrases, Representations (promoter: Prof. Dariusz Czaja), presented at the Institute of Ethnology and Cultural Anthropology, Jagiellonian University, in 2016. The author deals with the development of research focused on the painting, the rediscovery of Botticelli’s works by pre-Raphaelites, and their subsequent representation in culture
The working time regulation in JustEatTakeaway supplementary company agreement for Takeaway.com Express Italy (Just Eat group) riders
Get PDFConsidering that the regulation of the time and the possible economic relevance of the phases of waiting for delivery is a field of discussion still access regarding the work of riders, the Author analyzes, in detail, how the JustEatTakeway supplementary company agreement regulates
the working hours of riders. The Author illustrates the discipline contained in the CCNL Logistica,Trasporto, Merci e Spedizione and in the Protocol signed on July 18, 2018 for the same sector, to which the same company agreement in comment refers
- …
