Manned missions beyond low-Earth orbit present tremendous, multifaceted radiological challenges. The deep space radiation environment contains high-energy protons and heavy ions, which are not sufficiently shielded by the aluminum alloys that have historically been used in spacecraft. To address these shielding concerns, polymer-based nanocomposites have been proposed. Radiation transport simulations...
A linearized model with two vertical modes has been developed to understand observed characteristics of monthly variability in the Equatorial Pacific from TOPEX/POSEIDON measurements of Sea Surface Height (SSH). The 2-mode model is obtained from an equatorial beta plane model that has been linearized about a geostrophically balanced mean flow...
A statistically consistent and physically realistic approach for validating vector magnitude measurements is developed, based on a model for random measurement noise that explicitly satisfies a nonnegativity constraint for all “noisy” vector magnitude measurements. Numerical and analytic approximations are used to quantify the nonlinear functional dependence of sample conditional means...
Wind measurements by the National Aeronautics and Space Administration (NASA) scatterometer (NSCAT) and the SeaWinds scatterometer on the NASA QuikSCAT satellite are compared with buoy observations to establish that the accuracies of both scatterometers are essentially the same. The scatterometer measurement errors are best characterized in terms of random component...
A satellite-derived Climatology of Global Ocean Winds (COGOW) on a 0.5° latitude by 0.5° latitude grid is presented based on 5-years (August 1999 July 2004) of measurements from the SeaWinds scatterometer that was launched on 19 June 1999 onboard the QuikSCAT satellite. SeaWinds is an active microwave radar that estimates...
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5. An example three-day composite average of ocean wind speeds at a 10 m height
over 0.25° x
One year of collocated, rain-free normalized backscatter cross-section measurements from the Tropical Rainfall Mapping Mission (TRMM) precipitation radar (PR) and wind speed estimates from the TRMM Microwave Imager are used to construct fully empirical model functions relating cross section to wind speed for incidence angles from 0° (nadir) to 18°....
Vector winds measured by the Seasat-A Satellite Scatterometer (SASS) are analyzed to determine the spatial structure of oceanic surface winds over wavelengths from 200 to 2200 km. The analysis is performed in four latitudinal bands in the Pacific Ocean. Sampling characteristics of SASS preclude the possibility of determining full two-dimensional...