Computer Sciences Corporation

About: Computer Sciences Corporation is a based out in . It is known for research contribution in the topics: Spacecraft & Software development. The organization has 1916 authors who have published 2389 publications receiving 62729 citations. The organization is also known as: CSC.

Monte Carlo Simulation of the Effect of Soil Moisture Variation on the Microwave Emission from Soils

Abstract: In this paper, results of a Monte Carlo simulation of the effect of noise on the relationship between the microwave emissivity of soil and its moisture content are presented. It is found that whenever the magnitude of the noise for the independent variable, in this case the soil moisture, is increased, both the slope of the regression and the correlation coefficient decrease. In particular, when the noise has a magnitude equivalent to a coefficient of variation of 0.25, the slope and correlation coefficient are in good agreement with those obtained from the data of a 21-cm airborne microwave radiometer which was flown over a test site in Hand County, South Dakota. The comparison was made using a linear relationship to determine the estimated emissivity from the ground measurements of soil moisture. The linear relationship was derived from a radiative transfer model calculation of the microwave emissivities using realistic soil-moisture profiles. The effect of surface roughness was included in the relationship, and the variability of the surface roughness was also simulated by a Monte Carlo technique.

FUSE attitude control : target recognition and fine guidance performance

Abstract: The FUSE satellite employs innovative techniques for autonomous target acquisitions and fine pointing control. One of two Fine Error Sensors, incorporated in the optical path of the science instrument, provide the Instrument Data System computer with images, for target identification, and field star centroids, for fine pointing information to the spacecraft attitude control system. A suite of 'toolbox' functions has been developed to locate stars, selected and track on 'unknown' guide stars from the image, identify the star field, track preselected 'known' guide stars, follow moving targets, and provide pointing optimizations to fine- tune the centering of a target. After a maneuver to a new field, initial attitude is determined by identifying stars found in a 20' X 20' image. Identification is done by matching stars with an uploaded table of up to 200 objects selected from the Hubble Space Telescope (HST) Guide Star Catalog (GSC), ranging from V equals 9 to 13.5 mag., and typically covering a one degree field around the target. During identification, tracking is performed on unidentified stars in the image to prevent the satellite from drifting. A corrective slew is then commanded to place the target at the desired position. Tracking is then resumed on preselected guide stars. If desired, further fine alignment of the science apertures is performed by a target peakup using the FUV detectors. We discuss the target acquisition process; end-to- end performance; and problems encountered due to the limitations of the small field of view of the FES, HST GSC errors, and stray light in the telescope baffles.

Fiber optic fluorometer based on a dual-wavelength laser excitation source

Abstract: A remote fiber optic fluorometer system which incorporates a dual wavelength UV laser excitation source is described. The system provides increased specificity for detection of multiple fluorophores without sacrificing real time sensing capability. Limitations imposed by UV transmission in fused silica fibers are discussed.

Configuring processing relationships among entities of an organization

Abstract: A system, method and carrier medium for configuring processing relationships among entities of a Financial Service Organization (FSO). The system, method and carrier medium may be used for processing and reporting FSO business data including transactional data. A business structure, which may include the processing relationship between various entities of the FSO, may be defined. A processing relationship configuration program may be used to create a processing relationship structure. A node may be created and uniquely defined to represent an FSO physical entity and/or an FSO function. Nodes structures may be defined to correspond to the processing relationship structure within an FSO. A node number may uniquely identify a node instance in the processing relationship structure. An FSO database table may be used to store the a processing relationship structure information. FSO transactions, such as executing a report, may be generated based on the defined processing relationship structure.

Evaluation of Dispersion Forecasts Driven by Atmospheric Model Output at Coarse and Fine Resolution

Abstract: Lagrangian parcel models are often used to predict the fate of airborne hazardous material releases. The atmospheric input for these integrations is typically supplied by surrounding surface and upper-air observations. However, situations may arise in which observations are unavailable and numerical model forecasts may be the only source of atmospheric data. In this study, the quality of the atmospheric forecasts for use in dispersion applications is investigated as a function of the horizontal grid spacing of the atmospheric model. The Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) was used to generate atmospheric forecasts for 14 separate Dipole Pride 26 trials. The simulations consisted of four telescoping one-way nested grids with horizontal spacings of 27, 9, 3, and 1 km, respectively. The 27- and 1-km forecasts were then used as input for dispersion forecasts using the Hazard Prediction Assessment Capability (HPAC) modeling system. The resulting atmospheric and dispersion for...