1,721,093 research outputs found
Competition in UK Higher Education: Applying Porter's diamond model to geography departments
No full textIn a linked paper (Curran, 2000) Porter's diamond model of competitive advantage was proposed as a framework with which to evaluate the research performance of departments in UK higher education institutions. This article discusses the application of this model to an initial dataset of thirty-six departmental and institutional variables (later reduced to eight) for sixty-eight departments of geography. Approximately two-thirds of the variability in the results of the 1996 research assessment exercise (RAE) was accounted for using quantitative measures, leaving approximately one-third of the variability accounted for by the judgement of the RAE panel. These quantitative and qualitative measures were used to locate departments of geography along a spectrum of development from factor-driven (similar performance to that of institution as only factor conditions in place) to investment-driven (heavy investment leading to an upgrade of factor conditions, demand conditions and departmental strategy, structure and rivalry) to innovation-driven (four corners of diamond in place leading to continuous innovation/upgrading) and finally wealth-driven (seeking advantage through accumulated wealth leading to gradual decline). The most research successful departments were those in the innovation-driven stage. UK geography was seen to have a large proportion of its departments in the investment-driven stage with several in, or moving into, the innovation-driven stage. This bodes well for the future vitality of the discipline. <br/
Remote sensing: Using the spatial domain
No full textObjects in the terrestrial environment interact differentially with electromagnetic radiation according to their essential physical, chemical and biological properties. This differential interaction is manifest as variability in scattered radiation according to wavelength, location, time, geometries of illumination and observation and polarization. If the population of scattered radiation could be measured, then estimation of these essential properties would be straightforward. The only problem would be linking such estimates to environmental variables of interest. This review paper is divided into three parts. Part 1 is an overview of the attempts that have been made to sample the five domains of scattered radiation (spectral, spatial, temporal, geometrical, polarization) and then to use the results of this sampling to estimate environmental variables of interest. Part one highlights three issues: first, that relationships between remotely sensed data and environmental variables of interest are indirect; second, our ability to estimate these environmental variables is dependent upon our ability to capture a sound representation of variability in scattered radiation and third, a considerable portion of the useful information in remotely sensed images resides in the spatial domain (within the relations between the pixels in the image). This final point is developed in Part 2 that explores ways in which the spatial domain is utilized to describe spatial variation in remotely sensed and ground data; to design optimum sampling schemes for image data and ground data and to increase the accuracy with which remotely sensed data can be used to estimate both discontinuous and continuous variables. Part 3 outlines two specific uses of information in the spatial domain; first, to select an optimum spatial resolution and second, to inform an image classification.<br/
Monitoring urban growth on the European side of the Istanbul metropolitan area
No full textIstanbul is the largest city of Turkey with an area of around 5,750 km2 and a
population of around 10.8 M (2000). However, in 1980 the population was only
around 4.7 M and has more than doubled in only two decades. In 2000 around 65%
of the population were living on the European side of the city with its large
industrial/commercial and trade centres. The population is increasing as a result of
both (i) births exceeding deaths and (ii) mass immigration. Consequently planed and
unplanned housing is increasing while green areas are decreasing in area.
Monitoring metropolitan growth will enable us to better understand and manage this
complex urban area.
The primary aim of this research was to quantify urban growth on the European side
of Istanbul. Six land covers were identified in space and time using Landsat 5 TM
images for 1987, 1992, 1997 and 2001 and the differences in land cover area
between these dates was used to determine the rate of change. The accuracy of land
cover maps was determined using aerial photographs, field surveys and topographic
maps. The overall classification accuracy was between 80-86 %; urban areas
increased by around 1,000 ha yr-1 and forest, semi-natural vegetation, crop and bare
soil areas decreased collectively at a similar rate. The paper ends with a discussion
of the relation between the urban growth and population growth
The MERIS Terrestrial Chlorophyll Index
No full textThe long wavelength edge of the major chlorophyll absorption feature in the spectrum of a vegetation canopy moves to longer wavelengths with an increase in chlorophyll content. The position of this red-edge has been used successfully to estimate, by remote sensing, the chlorophyll content of vegetation canopies. Techniques used to estimate this red-edge position (REP) have been designed for use on small volumes of continuous spectral data rather than the large volumes of discontinuous spectral data recorded by contemporary satellite spectrometers. Also, each technique produces a different value of REP from the same spectral data and REP values are relatively insensitive to chlorophyll content at high values of chlorophyll content. This paper reports on the design and indirect evaluation of a surrogate REP index for use with spectral data recorded at the standard band settings of the Medium Resolution Imaging Spectrometer (MERIS). This index, termed the MERIS terrestrial chlorophyll index (MTCI), was evaluated using model spectra, field spectra and MERIS data. It was easy to calculate (and so can be automated), was correlated strongly with REP but unlike REP was sensitive to high values of chlorophyll content. As a result this index became an official MERIS level-2 product of the European Space Agency in March 2004. Further direct evaluation of the MTCI is proposed, using both greenhouse and field data
Evaluation of the MERIS Terrestrial Chlorophyll Index (MTCI)
No full textThe MEdium Resolution Imaging Spectrometer
(MERIS), one of the payloads on Envisat, has fine spectral
resolution, moderate spatial resolution and a three day repeat
cycle. This makes MERIS a potentially valuable sensor for the
measurement and monitoring of terrestrial environments at
regional to global scales. The red edge, which results from an
abrupt change in reflectance in red and near-infrared
wavelength has a location that is related directly to the
chlorophyll content of vegetation. A new index called the MERIS
terrestrial chlorophyll index (MTCI) uses data in three red/NIR
wavebands centred at 681.25nm, 705nm and 753.75nm (bands 8,
9 and 10 in the MERIS standard band setting). The MTCI is easy
to calculate and can be automated. Preliminary indirect
evaluation using model, field and MERIS data suggested its
sensitivity, to notably high values of chlorophyll content and its
limited sensitivity to spatial resolution or atmospheric effects. As
a result this index is now a standard level-2 product of the
European Space Agency.
For direct MTCI evaluation two different approaches were used.
First, the MTCI/chlorophyll content relationship were
determined using a chlorophyll content surrogate for sites in
southern Vietnam and second, the MTCI/chlorophyll
relationship was determined using actual chlorophyll content for
sites in the New Forest, UK and for plots in the greenhouse.
Forests in southern Vietnam were contaminated heavily with
Agent Orange during the Vietnam War. The contamination level
was so high that it led to a long term decrease in chlorophyll
content within forests that have long since regained full canopy
cover. In this approach the amount of Agent Orange dropped on
to the forest between 1965 and 1971 was used as a surrogate
(inverse) for contemporary chlorophyll content and was related
to current MTCI at selected forest sites. The resulting
relationship was negative. Further per pixel investigation of the
MTCI/Agent Orange concentration relationship is under way for
large forest regions. In the second approach MTCI was related
directly to chlorophyll content at two scales and the initial
resulting relationships were positive. Further plans involve the
evaluation of the MTCI at local, regional and eventually global
scales
Evaluation of the MERIS Terrestrial Chlorophyll Index
No full textThe medium resolution imaging spectrometer (MERIS), one of the payloads on Envisat, has fine spectral resolution, moderate spatial resolution and a three day repeat cycle. This makes MERIS a potentially valuable sensor for the measurement and monitoring of terrestrial environments at regional to global scales. The red edge, which results from an abrupt change in reflectance in red and near-infrared wavelength has a location that is related directly to the chlorophyll content of vegetation. A new index called the MERIS terrestrial chlorophyll index (MTCI) uses data in three red/NIR wavebands centred at 681.25 nm, 705 nm and 753.75 nm (bands 8, 9 and 10 in the MERIS standard band setting). The MTCI is easy to calculate and can be automated. Preliminary indirect evaluation using model, field and MERIS data suggested its sensitivity, to notably high values of chlorophyll content and its limited sensitivity to spatial resolution or atmospheric effects. As a result this index is now a standard level-2 product of the European Space Agency. For direct MTCI evaluation two different approaches were used. First, the MTCI/chlorophyll content relationship were determined using a chlorophyll content surrogate for sites in southern Vietnam and second, the MTCI/chlorophyll relationship was determined using actual chlorophyll content for sites in the New Forest, UK and for plots in the greenhouse. Forests in southern Vietnam were contaminated heavily with Agent Orange during the Vietnam War. The contamination level was so high that it led to a long term decrease in chlorophyll content within forests that have long since regained full canopy cover. In this approach the amount of Agent Orange dropped on to the forest between 1965 and 1971 was used as a surrogate (inverse) for contemporary chlorophyll content and was related to current MTCI at selected forest sites. The resulting relationship was negative. Further per pixel investigation of the MTCI/Agent Orange concentration relationship is under way for large forest regions. In the second approach MTCI was related directly to chlorophyll content at two scales and the initial resulting relationships were positive. Further plans involve the evaluation of the MTCI at local, regional and eventually global scales
Terrestrial MERIS
No full textThe Medium Resolution Imaging Spectrometer (MERIS) is one of a number of oceanographic imaging spectrometers inspired by the success of the Coastal Zone Colour Scanner (CZCS). Between 1988 (the first meeting of what was to become the MERIS Science Advisory Group) and the launch of Envisat in 2001, there has been a gradual re-branding of MERIS. It is now a sensor with a much broader environmental remit. Using MERIS's development history and by tracking key adaptations to its mission objectives, we demonstrate how its radiometric, spectral and geometric specifications can benefit terrestrial remote sensing, particularly at regional to global scale
Progress in hyperspectral remote sensing of terrestrial chlorophyll content
No full textInformation on the amount and spatial distribution of canopy chlorophyll content is of importance for the study of vegetation productivity and health, nutrient cycling, crop stress and crop yield, and most recently, for driving ecosystem simulation models from local to global scales. The amount of chlorophyll can be estimated using remotely sensed estimates of the wavelength location of the 'red edge'. This feature marks the boundary between high absorption in the red and high reflectance in the near infrared region of a vegetation reflectance spectrum and is visible in 'hyperspectral' spectra. Such spectra can be collected using laboratory (e.g., Perstorp NIRSystem 6500 spectrometer), field (e.g., Geophysical Environmental Research IRIS Mark IV), airborne (e.g., Airborne Visible/Infrared Imaging Spectrometer, AVIRIS) and more recently, spaceborne imaging spectrometers (e.g., MEdium Resolution Imaging Spectrometer, MERIS). The position of the red edge can be estimated (i) directly using methods such as maximum of first derivative spectra, linear interpolation, curve fitting and Lagrangian interpolation or (ii) indirectly using vegetation indices such as the MERIS Terrestrial Chlorophyll Index (MTCI). The former requires continuous spectral data recorded in narrow spectral bands and is therefore, limited to local scale applications, whereas the latter uses discontinuous spectral data of the type recorded by a spaceborne spectrometer and can therefore used for global scale applications. Over the past few decades the remote sensing of chlorophyll content has evolved from the development of empirical relationships between chlorophyll content and spectral reflectance in individual wavebands to the production of an operational product; weekly global terrestrial chlorophyll content maps derived from MERIS data. This paper will summarise the techniques and data used to estimate the chlorophyll content of vegetation and discuss some regional and global scale applications of such information
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