256 research outputs found

    Oceanography from Space: Phytoplankton Abundance

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    https://digitalcommons.cwu.edu/government_posters/1168/thumbnail.jp

    Factors Influencing the Rates, Processes and Magnitude of Accumulation of Carbon in Desert Soils

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    In 1991, the Soil Landscape Climate Program (SLCP) was organized as part of the Solid Earth Sciences Program at NASA. Part of the research to be conducted in the SLCP included studies of the systematics of carbon storage and flux in the terrestrial environment, specifically terrestrial soils. This report summarizes the results of the research funded through the SLCP that supported our efforts focussed on the nature of carbon behavior in arid environments, where the majority of the carbon is present as inorganic carbon stored as pedogenic carbonate in desert calcic soils

    Biogeochemical Processes in Sagebrush Ecosystems: Interactions with Terrain

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    Field data collection to support analysis of TM data was accomplished from June 22 to August 28th. Color infrared aerial photography acquired by a U2 on June 12, 1985 was used to locate and identify several vegetation communities. Forty sites where the USFS has collected long term ground cover were located in the field, delineated on aerial photos and ground photos of current conditions taken

    Assessment of Landsat for Rangeland Mapping, Rush Valley, Utah

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    The objective of this investigation is to assess the feasibility of using Landsat MSS (multispectral scanner) data to identify and map cover types for rangeland, and to determine comparative condition of the ecotypes. A supporting objective is to assess the utility of various forms of aerial photography in the process. If rangeland can be efficiently mapped with Landsat data, as supported by appropriate aerial photography and field data, then uniform standards of cover classification and condition may be applied across the rangelands of the state. Further, a foundation may be established for long-term monitoring of range trend, using the same satellite system over time

    Residents\u27 Annoyance Responses to Aircraft Noise Events

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    In a study conducted in the vicinity of Salt Lake City International Airport, community residents reported their annoyance with individual aircraft flyovers during rating sessions conducted in their homes. Annoyance ratings were obtained at different times of the day. Aircraft noise levels were measured, and other characteristics of the aircraft were noted by trained observers. Metrics commonly used for assessing aircraft noise were compared, but none performed significantly better than A-weighted sound pressure level. A significant difference was found between the ratings of commercial jet aircraft and general aviation propeller aircraft, with the latter being judged less annoying. After the effects of noise level were accounted for, no significant differences were found between the ratings of landings and take-offs. Aircraft noise annoyance reactions are stronger in lowered ambient noise conditions. This is consistent with the theory that reduced nighttime and evening ambient levels could create different reactions at different times of day. After controlling for ambient noise in a multiple regression analysis, no significant differences were found between the ratings of single events obtained during the three time periods: morning, afternoon, and evening

    Identifying Environmental Features for Land Management Decisions, Annual Report

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    This annual report outlines the major accomplishments of the Center for Remote Sensing and Cartography (CRSC) since the annual report was submitted in October 1982, with reference to the semiannual report of March 1983. The past year has been characterized by important progress in the research of digital processing techniques, completion of projects involving integrated remote sensing and environmental analysis, and interesting developments for new and continuing projects. Our computing strength is stronger than ever; we continue to rely primarily on the University of Utah Research Institute\u27s Prime computer and NASA\u27s Earth Resources Laboratory Applications Software (ELAS). We continue to maintain and develop the software in-house, and through interaction with the newly formed ELAS Users Group

    Motivation for Air-Launch: Past, Present, and Future

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    Air-launch is defined as two or more air-vehicles joined and working together, that eventually separate in flight, and that have a combined performance greater than the sum of the individual parts. The use of the air-launch concept has taken many forms across civil, commercial, and military contexts throughout the history of aviation. Air-launch techniques have been applied for entertainment, movement of materiel and personnel, efficient execution of aeronautical research, increasing aircraft range, and enabling flexible and efficient launch of space vehicles. For each air-launch application identified in the paper, the motivation for that application is discussed

    A spectral study of gamma-ray emitting AGN

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    In this paper we present a statistical analysis of the gamma-ray spectra of flat-spectrum radio quasars (FSRQ) compared to those of BL Lacs. The average spectra and possible systematic deviations from power-law behaviour are investigated by summing up the intensity and the power-law fit statistic for both classes of objects. We also compare the time-averaged spectrum to that at the time of gamma-ray outbursts. The spectrum of the average AGN is softer than that of the extragalactic gamma-ray background. It may be that BL Lacs, which on average have a harder spectrum than FSRQs, make up the bulk of the extragalactic background. We also find apparent cut-offs at both low and high energies in the spectra of FSRQs at the time of gamma-ray outbursts. While the cut-off at high energies may have something to do with opacity, the cut-off at low energies may be taken as indication that the gamma-ray emission of FSRQs is not a one component spectrum.Comment: 8 pages, accepted for publication in A&

    Kinematic Modeling of Separation Compression for Paired Approaches to Closely-Spaced Parallel Runways

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    In a simultaneous paired approach to closely-spaced parallel runways, a pair of aircraft flies in close proximity on parallel approach paths. The longitudinal separation between the aircraft must be maintained within a range that avoids wake encounters and, if one of the aircraft blunders, avoids collision. To increase operational availability, the approach procedure must accommodate a mixture of aircraft sizes and, consequently, approach speeds. In these procedures, the slower aircraft is placed in the lead position. The faster aircraft maintains separation from the slow aircraft in a dependent operation until final approach and flies independently afterward. Due to the higher approach speed of the fast aircraft, longitudinal separation will decrease during final approach. Therefore, the fast aircraft must position itself before the final approach so that it will remain within the safe range of separation as separation decreases. Given the approach geometry and speed schedule for each aircraft, one can use kinematics to estimate the separation loss between a pair of aircraft. A kinematic model can complement fast-time Monte-Carlo simulations of the approach by enabling a tailored reduction in the variation of starting position for the fast aircraft. One could also implement the kinematic model in ground-based or on-board decision support tools to compute the optimal initial separation for a given pair of aircraft. To better match the auto-coupled flight of real aircraft, the paper derives a kinematic model where the speed schedule is flown using equivalent airspeed. The predicted time of flight using the equivalent airspeed kinematic model compares well against a high-fidelity aircraft simulation performing the same approach. This model also demonstrates a modest increase in the predicted loss of separation when contrasted against a kinematic model that assumes the scheduled speed is true airspeed
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