Flexible DCP interface

The author has identified the following significant results. A user of an ERTS data collection system must supply the sensors and signal conditioning interface. The electronic interface must be compatible with the NASA-furnished data collection platform (DCP). A universal signal conditioning system for use with a wide range of environmental sensors is described. The interface is environmentally and electronically compatible with the DCP and has operated satisfactorily for a complete winter wheat growing season in Kansas

Performance of the Bowen ratio systems on a 22 deg slope

The Bowen ratio energy balance technique was used to assess the energy fluxes on inclined surfaces during the First ISLSCP Field Experiment (FIFE). Since air flow over sloping surface may differ from that over flat terrain, it is important to examine whether Bowen ratio measurements taken on sloping surfaces are valid. In this study, the suitability of using the Bowen ratio technique on sloping surfaces was tested by examining the assumptions that the technique requires for valid measurements. This was accomplished by studying the variation of Bowen ratio measurements along a selected slope at the FIFE site. In September 1988, four Bowen ratio systems were set up in a line along the 22 degree north-facing slope with northerly air flow (wind went up the slope). In July of 1989, six Bowen ratio systems were similarly installed with southerly air flow (the wind went down slope). Results indicated that, at distances between 10 to 40 meters from the top of the slope, no temperature or vapor pressure gradient parallel to the slope was detected. Uniform Bowen ratio values were obtained on the slope, and thus the sensible or latent heat flux should be similar along the slope. This indicates that the assumptions for valid flux measurements are reasonably met at the slope. The Bowen ratio technique should give the best estimates of the energy fluxes on slopes similar to that in this study

A study of the surface energy balance on slopes in a tallgrass prairie

Four slopes (north, south, east, and west) were selected on the Konza Prairie Research Natural Area to study the effect of topography on surface energy balance and other micrometeorological variables. Energy fluxes, air temperature, and vapor pressure were measured on the sloped throughout the 1988 growing season. Net radiation was the highest on the south-facing slope and lowest on the north-facing slope, and the difference was more than 150 W/sq m (20 to 30 percent) at solar noon. For daily averages, the difference was 25 W/sq m (15 percent) early in the season and increased to 60 W/sq m (30 to 50 percent) in September. The east-facing and west-facing slopes had the same daily average net radiation, but the time of day when maximum net radiation occurred was one hour earlier for the east-facing slope and one hour later for the west-facing slope relative to solar noon. Soil heat fluxes were similar for all the slopes. The absolute values of sensible heat flux (h) was consistently lower on the north-facing slope compared with other slopes. Typical difference in the values of H between the north-facing and the south-facing slopes was 15 to 30 W/sq m. The south-facing slope had the greatest day to day fluctuation in latent heat flux as a result of interaction of net radiation, soil moisture, and green leaf area. The north-facing slope had higher air temperatures during the day and higher vapor pressures both during the day and at night when the wind was from the south

Private Military and Security Labour Migration: the Case of Fiji

Private military and security companies (PMSCs) are a fast-growing global industry. While the rise of PMSCs and their activities have attracted much media coverage and growing scholarly attention, little is known about their sourcing of masses of military labour from the global South. This exploratory study examines the case of Fiji, whose thousands of ex/current disciplinary force personnel and unemployed men have been contracted by PMSCs to provide security work in Iraq and other high-conflict areas. The article shows this to be an instance of unequal core-periphery military labour trade, outlining its scale, processes and impacts on the migrants. It also illuminates how the migrants’ collective agency is demonstrated even under powerful structural constraints

Playing on the global periphery: Social scientific explorations of rugby in the Pacific Islands

In this prologue, we will briefly revisit some of the main research findings that have emerged from our collaborative work on Fiji rugby, as well as reflecting on some of the recommendations derived from our empirical investigation. We discuss issues in relation to national identity and migrations, post-rugby career-related retirement issues and alternative emerging cultural practices that challenge the dominant discourse around Fiji rugby. We then turn our attention to the content of this special issue and briefly introduce the articles included, with the main recommendation that there is a growing need to explore absent and emerging voices and cultural practices in regard to sport-related migration in, from and to the Pacific Islands

Double-trouble: Negotiating Gender and Sexuality in Post-colonial Women’s Rugby in Fiji

Although women’s exclusion in sport has attracted significant attention in the western context, similar issues in relation to post-colonial societies have remained in the margins of the sociology of sport. By analysing primary, interview-based evidence, in this article we explore the challenges female rugby players face regarding gender and sexuality in Fiji; a male dominated post-colonial society. In particular, we focus on participants’ resistance to dominant cultural practices and ways in which they (re)negotiate gender norms and sexuality in a double-bind struggle against both traditional and sporting male hegemonies. We argue that the case of Fijian women rugby players illustrates an interplay between a multiplicity of power relations in sport in a post-colonial society and the resilience with which the athletes negotiate and respond to them, as well as the dynamic nature and the transformative potential of their everyday practices

Relating the radar backscattering coefficient to leaf-area index

The relationship between the radar backscattering coefficient of a vegetation canopy, sigma(0) sub can, and the canopy's leaf area index (LAI) is examined. The relationship is established through the development of a model for corn and sorghum and another for wheat. Both models are extensions of the cloud model of Attema and Ulaby (1978). Analysis of experimental data measured at 8.6, 13.0, 17.0, and 35.6 GHz indicates that most of the temporal variations of sigma(0) sub can can be accounted for through variations in green LAI alone, if the latter is greater than 0.5

Estimated winter wheat yield from crop growth predicted by LANDSAT

An evapotranspiration and growth model for winter wheat is reported. The inputs are daily solar radiation, maximum temperature, minimum temperature, precipitation/irrigation and leaf area index. The meteorological data were obtained from National Weather Service while LAI was obtained from LANDSAT multispectral scanner. The output provides daily estimates of potential evapotranspiration, transpiration, evaporation, soil moisture (50 cm depth), percentage depletion, net photosynthesis and dry matter production. Winter wheat yields are correlated with transpiration and dry matter accumulation