38 research outputs found

    Cloud cover estimation: Use of GOES imagery in development of cloud cover data base for insolation assessment

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    The potential of using digital satellite data to establish a cloud cover data base for the United States, one that would provide detailed information on the temporal and spatial variability of cloud development are studied. Key elements include: (1) interfacing GOES data from the University of Wisconsin Meteorological Data Facility with the Jet Propulsion Laboratory's VICAR image processing system and IBIS geographic information system; (2) creation of a registered multitemporal GOES data base; (3) development of a simple normalization model to compensate for sun angle; (4) creation of a variable size georeference grid that provides detailed cloud information in selected areas and summarized information in other areas; and (5) development of a cloud/shadow model which details the percentage of each grid cell that is cloud and shadow covered, and the percentage of cloud or shadow opacity. In addition, comparison of model calculations of insolation with measured values at selected test sites was accomplished, as well as development of preliminary requirements for a large scale data base of cloud cover statistics

    Cloud cover typing from environmental satellite imagery. Discriminating cloud structure with Fast Fourier Transforms (FFT)

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    The use of two dimensional Fast Fourier Transforms (FFTs) subjected to pattern recognition technology for the identification and classification of low altitude stratus cloud structure from Geostationary Operational Environmental Satellite (GOES) imagery was examined. The development of a scene independent pattern recognition methodology, unconstrained by conventional cloud morphological classifications was emphasized. A technique for extracting cloud shape, direction, and size attributes from GOES visual imagery was developed. These attributes were combined with two statistical attributes (cloud mean brightness, cloud standard deviation), and interrogated using unsupervised clustering amd maximum likelihood classification techniques. Results indicate that: (1) the key cloud discrimination attributes are mean brightness, direction, shape, and minimum size; (2) cloud structure can be differentiated at given pixel scales; (3) cloud type may be identifiable at coarser scales; (4) there are positive indications of scene independence which would permit development of a cloud signature bank; (5) edge enhancement of GOES imagery does not appreciably improve cloud classification over the use of raw data; and (6) the GOES imagery must be apodized before generation of FFTs

    Upgrade of Fermilab/Nicadd Photoinjector Laboratory

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    Efficiency of the Summer Monsoon in Generating Streamflow Within a Snow‐Dominated Headwater Basin of the Colorado River

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    The North American Monsoon occurs July–September in the central Rocky Mountains bringing significant rainfall to Colorado River headwater basins. This rain may buffer streamflow deficiencies caused by reductions in snow accumulation. Using a data-modeling framework, we explore the importance of monsoon rain in streamflow generation over historical conditions in an alpine basin. Annually, monsoon rain contributes 18 ± 7% water inputs and generates 10 ± 6% streamflow. The bulk of rain supports evapotranspiration in lower subalpine forests. However, rains have the potential to produce appreciable streamflow at higher elevations where soil moisture storage, forest cover, and aridity are low and rebound late season streamflow 64 ± 13% from simulated reductions in spring snowpack as a function of monsoon strength. Interannual variability in monsoon efficiency to generate streamflow declines with low snowpack and high aridity, implying the ability of monsoons to replenish streamflow in a warmer future with less snow accumulation will diminish

    Dėmesys technologijoms: rūpestis ar technologija?

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    The paper analyses different attitudes towards technologies in contemporary philosophical discourses. It points out that classical notion of technology formulated by Martin Heidegger seems to be more and more often questioned and even forgotten. As a result, it is being replaced by the theory of determinism, according to which the change of technologies determines the changes in social systems, the human being including. This happens this way and not vice versa. Nowadays technē, or “technika” (in English: technology) is mostly understood in the instrumental meaning or in the meaning of power. It is considered to be a powerful means, tool or mechanism to influence, change, control and manipulate human consciousness and human feelings. Despite the fact that technologies have already been tamed, the problem of huge responsibility for using and developing them arises. It is questioned whether the increasing society’s attention to modern technologies is not a particular “technology” of the postmodern capitalism to manipulate social consciousness. In parallel with “yes” answer to this question, Albert Borgmann’s idea that the causes of technological development have an ontological dimension, i.e. the causes are rooted in the nature of human beings themselves and their desire to adore own creativity, is discussed. Thus, it becomes necessary to probe deeper into the nature of creativity
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