452 resultados para Sabo, Chris
em CentAUR: Central Archive University of Reading - UK
Resumo:
A method has been developed to estimate Aerosol Optical Depth (AOD), Fine Mode Fraction (FMF) and Single Scattering Albedo (SSA) over land surfaces using simulated Sentinel-3 data. The method uses inversion of a coupled surface/atmosphere radiative transfer model, and includes a general physical model of angular surface reflectance. An iterative process is used to determine the optimum value of the aerosol properties providing the best fit of the corrected reflectance values for a number of view angles and wavelengths with those provided by the physical model. A method of estimating AOD using only angular retrieval has previously been demonstrated on data from the ENVISAT and PROBA-1 satellite instruments, and is extended here to the synergistic spectral and angular sampling of Sentinel-3 and the additional aerosol properties. The method is tested using hyperspectral, multi-angle Compact High Resolution Imaging Spectrometer (CHRIS) images. The values obtained from these CHRIS observations are validated using ground based sun-photometer measurements. Results from 22 image sets using the synergistic retrieval and improved aerosol models show an RMSE of 0.06 in AOD, reduced to 0.03 over vegetated targets.
Resumo:
A method has been developed to estimate aerosol optical depth (AOD) over land surfaces using high spatial resolution, hyperspectral, and multiangle Compact High Resolution Imaging Spectrometer (CHRIS)/Project for On Board Autonomy (PROBA) images. The CHRIS instrument is mounted aboard the PROBA satellite and provides up to 62 bands. The PROBA satellite allows pointing to obtain imagery from five different view angles within a short time interval. The method uses inversion of a coupled surface/atmosphere radiative transfer model and includes a general physical model of angular surface reflectance. An iterative process is used to determine the optimum value providing the best fit of the corrected reflectance values for a number of view angles and wavelengths with those provided by the physical model. This method has previously been demonstrated on data from the Advanced Along-Track Scanning Radiometer and is extended here to the spectral and angular sampling of CHRIS/PROBA. The values obtained from these observations are validated using ground-based sun-photometer measurements. Results from 22 image sets show an rms error of 0.11 in AOD at 550 nm, which is reduced to 0.06 after an automatic screening procedure.
Resumo:
We develop a method to derive aerosol properties over land surfaces using combined spectral and angular information, such as available from ESA Sentinel-3 mission, to be launched in 2015. A method of estimating aerosol optical depth (AOD) using only angular retrieval has previously been demonstrated on data from the ENVISAT and PROBA-1 satellite instruments, and is extended here to the synergistic spectral and angular sampling of Sentinel-3. The method aims to improve the estimation of AOD, and to explore the estimation of fine mode fraction (FMF) and single scattering albedo (SSA) over land surfaces by inversion of a coupled surface/atmosphere radiative transfer model. The surface model includes a general physical model of angular and spectral surface reflectance. An iterative process is used to determine the optimum value of the aerosol properties providing the best fit of the corrected reflectance values to the physical model. The method is tested using hyperspectral, multi-angle Compact High Resolution Imaging Spectrometer (CHRIS) images. The values obtained from these CHRIS observations are validated using ground-based sun photometer measurements. Results from 22 image sets using the synergistic retrieval and improved aerosol models show an RMSE of 0.06 in AOD, reduced to 0.03 over vegetated targets.
Resumo:
Automatic tracking of vorticity centers in European Centre for Medium-Range Weather Forecasts analyses has been used to develop a 20-yr climatology of African easterly wave activity. The tracking statistics at 600 and 850 mb confirm the complicated easterly wave structures present over the African continent. The rainy zone equatorward of 15 degreesN is dominated by 600-mb activity, and the much drier Saharan region poleward of 15 degreesN is more dominated by 850-mb activity. Over the Atlantic Ocean there is just one storm track with the 600- and 850-mb wave activity collocated. Based on growth/decay and genesis statistics, it appears that the 850-mb waves poleward of 15 degreesN over land generally do not get involved with the equatorward storm track over the ocean. Instead, there appears to be significant development of 850-mb activity at the West African coast in the rainy zone around (10 degreesN, 10 degreesW), which, it is proposed, is associated with latent heat release. Based on the tracking statistics, it has been shown that there is marked interannual variability in African easterly wave (AEW) activity. It is especially marked at the 850-mb level at the West African coast between about 10 degrees and 15 degreesN, where the coefficient of variation is 0.29. For the period between 1985 and 1998, a notable positive correlation is seen between this AEW activity and Atlantic tropical cyclone activity. This correlation is particularly strong for the postreanalysis period between 1994 and 1998. This result suggests that Atlantic tropical cyclone activity may be influenced by the number of AEWs leaving the West African coast, which have significant low-level amplitudes, and not simply by the total number of AEWs.
Resumo:
We investigated processing of wh-questions and declarative sentences with differing syntactic complexity in a case of mixed dementia (FA). FA was impaired in her ability to understand syntactically complex declarative sentences and syntactically complex wh-questions beginning with which but not complex who questions. This profile, novel in dementia, is similar to that reported for people with agrammatic aphasia and discerns a ‘‘fault line’’ of the language system along a syntactic/semantic parameter
Resumo:
This major curated exhibition, publication and events builds on Rowlands’ curatorial research. Working in collaboration with co-curators Martin Clark, Artistic Director, Tate St Ives and Michael Bracewell, cultural historian, the exhibition sought to explore new narratives within British art. The innovative curatorial methodology developed from a fiction found in the infamous novel, The Dark Monarch by Sven Berlin, Gallery Press 1962. The research sought specific archival and collection work that allowed thematic strands to emerge that represented influences across generations. The exhibition features two-hundred artworks, from the Tate Collection, archives and other significant British public and private collections. It examines the development of early Modernism, in the UK, as well as the reappearance of esoteric and arcane references in a significant strand of contemporary art practice. Historical works from Samuel Palmer, Graham Sutherland, Henry Moore and Paul Nash are shown alongside contemporary artists including Derek Jarman, Cerith Wyn Evans, Eva Rothschild, Linder and John Russell. The exhibition includes a key work by Damien Hirst ¬ the first time he has been shown at Tate St Ives and a number of contemporary commissions. The Dark Monarch publication extended the discourse of the research critically examining the tension between progressive modernity and romantic knowledge, the book focuses on the way that artworks are encoded with various histories - geological, mythical and magical. Essays examine magic as a counterpoint to modernity’s transparency and rational progress, but also draw out the links modernity has with notions such as fetishism, mana, totem, and the taboo. Often viewed as counter to Modernism, this collection of essays suggest that these products of illusion and delusion in fact belong to modernity. Drawing together 15 different writers commissioned to explore magic as a counterpoint of liberal understanding of modernity, drawing out links that modernity has with notions of fetish, taboo and occult philosophy. Including essays by Marina Warner, Ilsa Colsell, Philip Hoare, Chris Stephens, Jennifer Higgie and Morrissey.
Resumo:
The professional development certificate scheme, developed by the British Pharmaceutical Students’ Association, can bridge the gap between pharmacy undergraduates, tutors and employers. Jamie Wilkinson, Chris Cairns and Parastou Donyai explain.
Resumo:
Rights as well as democracy play a crucial role in the legitimacy of the EU and constitutional patriotism has been influential in attempting to link them together. The article seeks to engage in a critique of constitutional patriotism on two fronts. First, it distinguishes between the various types of right that exist within EU law-Community, citizenship and fundamental-and then analyses the place of these rights within various political models of the EU ranging from nationalism to republicanism. It argues that constitutional patriotism does not enjoy a monopoly on rights discourse in the EU: most models of the EU see a place for rights; it is just that the type of right supported varies. Secondly, advocates of constitutional patriotism argue that EU rights generate European identity. The article questions the extent to which this is the case, arguing that identity potential varies considerably according to the type of EU right concerned.