Spatio-temporally variable information on total vegetation cover is highly relevant to water quality and land management in river catchments adjacent to the Great Barrier Reef, Australia. A time series of the global Moderate Resolution Imaging Spectroradiometer (MODIS) Fraction of Photosynthetically Active Radiation (FPAR; 2000-2006) and its underlying biome classification (MOD12Q1) were compared to national land cover and regional, remotely sensed products in the dry-tropical Burdekin River. The MOD12Q1 showed reasonable agreement with a classification of major vegetation groups for 94% of the study area. We then compared dry-seasonal, quality controlled MODIS FPAR observations to (i) Landsat-based woody foliage projective cover (wFPC) (2004) and (ii) MODIS bare ground index (BGI) observations (2001-2003). Statistical analysis of the MODIS FPAR revealed a significant sensitivity to Landsat wFPC-based Vegetation Structural Categories (VSC) and VSC-specific temporal variability over the 2004 dry season. The MODIS FPAR relation to 20 coinciding MODIS BGI dry-seasonal observations was significant ( < 0.001) for homogeneous areas of low wFPC. Our results show that the global MODIS FPAR can be used to identify VSC, represent VSC-specific variability of PAR absorption, and indicate that the amount, structure, and optical properties of green and non-green vegetation components contribute to the MODIS FPAR signal.
Increasing population growth and growing ecological problems in urban areas require advanced remote sensing technology for the acquisition of detailed and accurate land-use information for urban management and planning issues. Surface consumption of 120 ha per day (2003) for traffic and settlement areas in Germany is far away from the 30 ha per day of the sustainability-strategy intended for the year 2020 by the Federal Environmental Ministry. With regard to the 50ies, imperviousness and sealing almost doubled. The presented study is embedded in a project in North Rhine-Westphalia (NRW), the most densely populated federal state in Germany. During the last decades, industrial transformation processes as well as strong economic and socio-structural changes have taken place, making NRW most suitable as an exemplary region to study and visualize dynamic developments in Europe. The examined time period of this work includes intense urban development and expansion in the suburban regions. LANDSAT data of three time slices (1975, 1984 & 2001) build the backbone to detect the changes taken place. Applying a multisensoral approach with improved spatial and even spectral resolution the focus is on the urban development of certain “hot spots” in NRW. CORONA, IKONOS as well as ASTER satellite data is used to allow a further characterization of urban land-use types and changes in more detail over the last four decades. Classical change detection methods as PCA are combined with classification of segmented urban land-use areas when evaluating the type of change.
The growth conditions for GaN/GaInN MQW structures have been studied in detail on AIX 2000 HT G3 Planetary Reactors. Major process variables, such as precursor supply, growth time and growth temperature have been varied. To describe the dependencies of MQW growth a second order polynomic model has been developed. The average prediction error within the model limits is 2.8 nm emission wavelength, in the range of 400 to 490 nm. The linear effects of the major growth parameters have been quantified. Additionally, statistically significant curvature factors have been identified as the product of growth time and temperature, the square of the TMIn molar supply rate and the square of the growth time. To increase the system throughput for mass production applications the reactor geometry has been scaled up to 11x2" in the AIX 2400 HT G3 configuration recently. Numerical simulation of thermal field and decomposition chemistry has been performed for the new reactor set up. From the simulation results initial values for the respective process parameters have been chosen. The numerical growth parameter model has been transferred to the larger configuration and is verified with experimental results. Employing the 11x2' Planetary Reactor configuration an excellent on wafer uniformity of better than 0.2% (1 nm) standard deviation at 487 nm average peak wavelength has been shown. Wafer-to-wafer reproducibility has been demonstrated with a variation of 1.4 nm standard deviation and run-to-run with a variation of 0.25 nm standard deviation at an average wavelength of 470 nm for a full load of 11 wafers. The uniformities obtained are compared with results from the 6x2" configuration.
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