111,923 research outputs found
The application of hyperspectral image techniques on MODIS data for the detection of oil spill in RSA
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author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
The ESA LEARNEO! project for stimulating earth observation education
No full textLeanEO! is a 2-year Earth Observation education project funded by the European Space Agency (ESA) and developed by different European Institutions. Its main aim is to increase the understanding and knowledge of satellite data obtained from ESA missions and demonstrate how these can be used when faced with environmental problems in the real world. The project has developed hands-on training resources for use primarily (but not exclusively) by teachers and students at upper high school to university level. Each lesson comes complete with data, analysis tools and exhaustive background information necessary for the completion of the suggested activities and provides answers to the various study questions. Model answers are supplied for users working on their own or with limited specialist support. In this paper the aims and the opportunities provided by the project will be described in detail
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An optical model for the interpretation of remotely sensed multispectral images of oil spill
No full textThis work is focused on the interpretation of multispectral images of oil spills, by introducing an optical model of spectral signature for oil-covered sea surface. Oil spill detection and oil type identification can potentially be achieved using data from multispectral optical sensors. However, multispectral images interpretation is challenging, because the spectral signature depends not only on oil optical properties and film thickness, but also on the optical properties of the water column, the incident light distribution and the instrument viewing geometry. In this work a simulator has been developed, starting from an optical model for both clean and polluted surfaces, which makes it possible to analyze variability in the optical signal from an oil-covered water surface. Several simulations have been performed varying the water optical properties within a range typical of Case I waters, and considering different crude and refined oils. Incident light distributions and viewing configurations have been chosen according to a typical viewing geometry of the MERIS sensor over a particularly interesting Mediterranean area: the marine ecosystem of the Tuscan Archipelago. The results, shown in terms of both upwelling radiance and oil-water optical contrast, provide some general rules that may aid interpretation of MERIS data. In particular, the detectability of an oil slick has been shown to depend on oil type and film thickness: very thin oil films (sheens) are more easily detected at viewing directions near the sun-glint zone, while very thick films are more likely to be detected at viewing angles away from the sun. For films of intermediate thickness the detectability depends mainly on the oil's specific optical properties
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