16,817 research outputs found

    Spaceborne scanner imaging system errors

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    The individual sensor system design elements which are the priori components in the registration and rectification process, and the potential impact of error budgets on multitemporal registration and side-lap registration are analyzed. The properties of scanner, MLA, and SAR imaging systems are reviewed. Each sensor displays internal distortion properties which to varying degrees make it difficult to generate on orthophoto projection of the data acceptable for multiple pass registration or meeting national map accuracy standards and is also affected to varying degrees by relief displacements in moderate to hilly terrain. Nonsensor related distortions, associated with the accuracy of ephemeris determination and platform stability, have a major impact on local geometric distortions. Platform stability improvements expected from the new multi mission spacecraft series and improved ephemeris and ground control point determination from the NAVSTAR/global positioning satellite systems are reviewed

    Comparison of a model of Jupiter's magnetosphere with Pioneer data

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    A model of Jupiter's magnetosphere in which there is a circum-Jovian outflow of plasma from an inner corotating magnetodisc is compared with the observations of the Pioneer flybys

    Bulk Viscosity of Interacting Hadrons

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    We show that first approximations to the bulk viscosity ηv\eta_v are expressible in terms of factors that depend on the sound speed vsv_s, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of ηv\eta_v on the factor (13−vs2)(\frac 13 - v_s^2) is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature arise from particles which are neither extremely nonrelativistic nor extremely relativistic. Numerical results for a model binary mixture are reported.Comment: 4 pages, 1 figure, Contribution to Quark Matter 2009, Knoxville, Tennessee, US

    Three-isotope plot of fractionation in photolysis: A perturbation theoretical expression

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    The slope of the three-isotope plot for the isotopomer fractionation by direct or nearly direct photodissociation is obtained using a perturbation theoretical analysis. This result, correct to first order in the mass difference, is the same as that for equilibrium chemical exchange reactions, a similarity unexpected a priori. A comparison is made with computational results for N2O photodissociation. This theoretical slope for mass-dependent photolytic fractionation can be used to analyze the data for isotopic anomalies in spin-allowed photodissociation reactions. Earlier work on chemical equilibria is extended by avoiding a high-temperature approximation

    Current status of models of Jupiter's magnetosphere in the light of Pioneer data

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    The salient features of the various models of Jupiter's magnetosphere are compared with each other and with the major findings of Pioneer 10 and 11. No single model explains all the major phenomena detected by the Pioneers. A unified model of Jupiter's magnetosphere is proposed
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