3,727 research outputs found
NOSS altimeter algorithm specifications
A description of all algorithms required for altimeter processing is given. Each description includes title, description, inputs/outputs, general algebraic sequences and data volume. All required input/output data files are described and the computer resources required for the entire altimeter processing system were estimated. The majority of the data processing requirements for any radar altimeter of the Seasat-1 type are scoped. Additions and deletions could be made for the specific altimeter products required by other projects
A 94/183 GHz multichannel radiometer for Convair flights
A multichannel 94/183 GHz radiometer was designed, built, and installed on the NASA Convair 990 research aircraft to take data for hurricane penetration flights, SEASAT-A underflights for measuring rain and water vapor, and Nimbus-G underflights for new sea ice signatures and sea surface temperature data (94 GHz only). The radiometer utilized IF frequencies of 1, 5, and 8.75 GHz about the peak of the atmospheric water vapor absorption line, centered at 183.3 GHz, to gather data needed to determine the shape of the water molecule line. Another portion of the radiometer operated at 94 GHz and obtained data on the sea brightness temperature, sea ice signatures, and on areas of rain near the ocean surface. The radiometer used a multiple lens antenna/temperature calibration technique using 3 lenses and corrugated feed horns at 94 GHz and 183 GHz. Alignment of the feed beams at 94 GHz and 183 GHz was accomplished using a 45 deg oriented reflecting surface which permitted simultaneous viewing of the feeds on alternate cycles of the chopping intervals
Multi-physics ensemble snow modelling in the western Himalaya
Combining multiple data sources with multi-physics simulation frameworks offers new potential to extend snow model inter-comparison efforts to the Himalaya. As such, this study evaluates the sensitivity of simulated regional snow cover and runoff dynamics to different snowpack process representations. The evaluation is based on a spatially distributed version of the Factorial Snowpack Model (FSM) set up for the Astore catchment in the upper Indus basin. The FSM multi-physics model was driven by climate fields from the High Asia Refined Analysis (HAR) dynamical downscaling product. Ensemble performance was evaluated primarily using MODIS remote sensing of snow-covered area, albedo and land surface temperature. In line with previous snow model inter-comparisons, no single FSM configuration performs best in all of the years simulated. However, the results demonstrate that performance variation in this case is at least partly related to inaccuracies in the sequencing of inter-annual variation in HAR climate inputs, not just FSM model limitations. Ensemble spread is dominated by interactions between parameterisations of albedo, snowpack hydrology and atmospheric stability effects on turbulent heat fluxes. The resulting ensemble structure is similar in different years, which leads to systematic divergence in ablation and mass balance at high elevations. While ensemble spread and errors are notably lower when viewed as anomalies, FSM configurations show important differences in their absolute sensitivity to climate variation. Comparison with observations suggests that a subset of the ensemble should be retained for climate change projections, namely those members including prognostic albedo and liquid water retention, refreezing and drainage processes
Propulsion issues, options and trades
Several different types of propulsion concepts are discussed: pulsed fission; continuous nuclear fission; chemical; and chemical boost with advanced nuclear fission. Some of the key characteristics of each type are provided, and typical concepts of each are shown
Towards a value-centric approach to education: Implications of changing practices in construction project management
This article explores two interdependent subjects underpinning how the built environment is produced: value and integrated teamwork. The concept of value is defined as the relationship between benefits received and costs incurred. Value thereby derives from the values of the judge and in multi-stakeholder construction projects, understanding each membera??s unique value proposition is complex, forming a catalyst for integrated teamwork and interdisciplinary ways of working. These subjects are reviewed in relation to the changes occurring in practice and how they can help inform new approaches to the education of built environment professionals, giving specific attention to construction project management education. In exploring these themes, the authors first review related project management research, before focusing on construction and current trends in practice. The paper then summarises research aimed at developing better theories of value and advancing integrated teamwork in construction. A framework aimed at facilitating a move to an educational model that encompasses a value-based and multidisciplinary approach is presented, followed by discussion and future work
International Law and Conflict Resolution: Palestinian Claims and the Arab States
Over the last few years there has been a revival of interest in international law as a mechanism for conflict resolution. These same years have seen a demonstration of the undeveloped state of international law, particularly concerning intrastate conflicts. The wide disagreement about questions of fact, legal consequence, and world order implications of internal war is a telling commentary on the current problems of applying legal standards to such conflicts. A major part of the disagreement can be explained in terms of the specific problems relating to fact determination and authoritative interpretation engendered by the nature of the environment in which the international legal order must function. The ambiguous and emotionally charged atmosphere that is characteristic of all international actions when force or the threat of force is involved also contributes to the disagreement.
Conflicts such as the Arab-Israeli dispute clearly raise the question whether the traditional approaches and concepts of international law are adequate to characterize the range and variety of contemporary internal disorders and the types of involvement by third states. In addition, many international legal norms are not specific enough in content to allow illegal behavior to be identified with confidence. This is true especially of norms purporting to limit the use of coercion. Under the general heading of minor coercion, the many different forms of coercive influence have remained largely undifferentiated in law. The major problem is not the perennial one of making appropriate judgments about state behavior, but the more complex problem of constructing categories that will accurately reflect the changed and changing milieu in which the law must function
A 94/183 GHz aircraft radiometer system for Project Storm Fury
A radiometer design suitable for use in NASA's WB-57F aircraft to collect data from severe storm regions was developed. The design recommended was a 94/183 GHz scanning radiometer with 3 IF channels on either side of the 183.3 GHz water vapor line and a single IF channel for a low loss atmospheric window channel at 94 GHz. The development and construction of the 94/183 GHz scanning radiometer known as the Advanced Microwave Moisture Sounder (AMMS) is presented. The radiometer scans the scene below the aircraft over an angle of + or - 45 degrees with the beamwidth of the scene viewed of approximately 2 degrees at 94 GHz and 1 degree at 183 GHz. The AMMS data collection system consists of a microcomputer used to store the radiometer data on the flight cartridge recorder, operate the stepper motor driven scanner, and collect housekeeping data such as thermistor temperature readings and aircraft time code
David P. Forsythe and Charles J. Mach on Empire of Humanity: A History of Humanitarianism. By Michael Barnett. Ithaca, NY: Cornell University Press, 2011. 312pp.
A review of:
Empire of Humanity: A History of Humanitarianism. By Michael Barnett. Ithaca, NY: Cornell University Press, 2011. 312pp
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