3,864 research outputs found
LANDSAT 4 investigations of Thematic Mapper and Multispectral Scanner applications
Interband detector noise was suppressed in the TIPS TM North Dakota data by median filtering. Procedures were developed to optimize the visual information content of thematic mapper data and evaluate the resulting photographic products by visual interpretation. A digital to analog TM transfer function was developed which properly placed the digital values on the most useable portion of film response curve. Utilizing the calculated minimum, mean, and maximum and the respective standard deviations of the bands from 50 sample scenes of TM data, look up tables were designed which resulted in acceptable photographic products. These products were evaluated by generation of color composites of selected band combinations using standard photo production procedures, and visual interpretation of scene features
Testing Multiband and Multidate Photography for Crop Identification
Procedures used and results derived in a series of prerequisite interpretation tests that were performed on multiband and multidate photography are described. The results of these quantitative tests led to the selection of what was considered to be the best combination of multiband and multidate photographs for use in the Maricopa County Survey
LANDSAT 4 investigation of thematic mapper and multispectral scanner applications
Six different band combinations of TM data were selected for evaluation by four experienced photointerpreters who were asked to rank the band combinations according to the ease with which the category of image feature designated for each set of combinations could be distinguished. There were four sets of combinations selected for each category of image feature. Scenes of Oklahoma City, Oklahoma and of the Sacramento Valley, California area were enlarged to 1:250,000 and 2 cm circular chips were cut from each print. A nonparametric rank order test was carried out on the data to determine if the interpreters found no difference among the band combinations in ranking for the designated categories. Kendall's coefficient of concordance (W) was calculated and the significance of the W value was determined by a chi-square test. A table summarizes the results of the evaluation and shows the rank order of band combinations indicated as valid by rejection of the null hypothesis
Word of Mouth and Physician Referrals Still Drive Health Care Provider Choice
Examines how consumers choose physicians, specialists, or medical facilities, including the use of physician referrals, word-of-mouth recommendations, health plan information, and the Internet. Explores implications for consumer-directed health care
Designing Effective Health Care Quality Transparency Initiatives
Profiles two well-designed healthcare quality transparency initiatives from California and Massachusetts. Examines key design and implementation elements, including provider engagement, reliable data, consumer-friendliness, and feedback to providers
LANDSAT 4 investigations of thematic mapper and multispectral scanner applications
Digital data analyses suggest the potential for TM data to provide improved land cover information with the mid-IR band being especially useful. Coefficients of variations for major land categories were greater for MSS data channels than for TM channels. Interpretation of black and white images of the six reflective TM bands indicates a strong interpreter preference for bands 5 and 7 for making distinctions in most of the classification categories that were addressed; however, a strong case can be made for a color composite containing visible, near-IR, and mid-IR spectral regions when distinguishing vegetation. A transformation from each red, green, blue color space into hue, intensity, and saturation space has potential for enhanced interpretability of TM color composite images. A perspective view transformation was demonstrated that could be useful for presently registered layers of spatial data in an oblique view format
IFEMS, an Interactive Finite Element Modeling System Using a CAD/CAM System
A method of coupling a CAD/CAM system with a general purpose finite element mesh generator is described. The three computer programs which make up the interactive finite element graphics system are discussed
Testing the usefulness of ERTS-1 imagery for inventorying wildland resources in northern California
The usefulness of ERTS-1 imagery for inventorying wildland resources in northern California is discussed. Studies are being conducted in two large wildland areas, namely, the Feather River Watershed and the Northern Coastal Zone. The 2.5 million-acre Feather River headwaters area in northern California is the keystone watershed for the California Water Project, one of the most extensive and ambitious water resource developments ever attempted. Consequently, accurate and timely information on the quantity, quality and distribution of timber, forage, water and recreational resources is of immediate importance to each public agency and private group managing this vast, but inaccessible, wildland area. The Northern Coastal Zone (consisting of the counties of Marin, Sonoma, Mendicino, Humbolt and Del Norte) is relatively rural, with an economy based on agriculture, timber, commercial fishing and tourism. However, it is expected that intensive resource use resulting from increasing population will soon become a serious problem unless wise land use planning is undertaken. Thus, this coastal region is particularly well suited to investigations of the ways in which ERTS-1 imagery and other supporting data may be used in conducting land use evaluations
Physiological and Biochemical Responses of Bald Cypress to Salt Stress
Bald Cypress (Taxodium distichum (L.) Rich.) is native to freshwater wetlands of Florida. The vitality of cypress within coastal freshwater wetlands is threatened by saltwater intrusion. Biomarkers to detect sub-lethal salinity stress were developed using a controlled greenhouse study. Cypress saplings maintained at elevated salinities of 4 and 8‰ exhibited a decrease in maximum quantum yield (MQY) and an increase in non-photochemical quenching (NPQ). Cypress leaves exhibited an increase in Na+, H2O2, and free proline content compared to plants maintained in freshwater. These biomarkers were used to detect salinity stress within a population of cypress associated with the lower St. Johns River where saltwater intrusion is occurring. Cypress in a basin swamp exhibited signs of salinity stress with low MQY and elevated NPQ values compared to Cypress at other sites. Cypress leaves at the basin swamp also had the highest Na+, lipid peroxidation, and proline content compared to plants at other sites. Detached Cypress leaf experiments were conducted to explore the mechanisms of salt tolerance. Detached cypress leaves were first exposed to elevated NaCl concentrations for 24, 48, or 72 hours. Elevated salinity caused a decrease in leaf transpiration for all times tested. Total peroxidase activity exhibited an increase in response to salt stress after 48 hours. Enhanced peroxidase activity was found to be associated with the induction of a ~37 kDa peroxidase isoform. Treatment of leaves with clofibrate caused an increase in activity of the ~37 kDa peroxidase. Pre-treatment of leaves with brefeldin A (BFA) blocked the induction of the ~37 kDa peroxidase associated with salt stress. Pre-treatment of Cypress leaves with diphenyliodonium (DPI) blocked the decrease in transpiration associated with salt stress, suggesting that H2O2 is enzymatically produced within the stomata in response to salt stres
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