Relationships between chlorophyll density and ocean radiance as measured by U2/OCS: Algorithms, examples and comparison

An ocean atmosphere radiative transfer process computation method which is suitable for determining lower boundary ocean albedo and other radiation components from spectral measurements of upwelling radiance taken from a high altitude platform is described. The method was applied to a set of color scanner data taken from slope water of the South Atlantic Bight to determine the influence of cholorophyll-a pigments in the sea on the ratio of upwelling radiance to down welling irradiance as a function of wavelength. The resulting chlorophyll concentrations are compared with measurements made by ships stationed along the flight path

A computer algorithm for performing interactive algebraic computation on the GE Image-100 system

A subroutine which performs specialized algebraic computations upon ocean color scanner multispectral data is presented. The computed results are displayed on a video display. The subroutine exists as a component of the aircraft sensor analysis package. The user specifies the parameters of the computations by directly interacting with the computer. A description of the conversational options is also given

The results of initial analysis of OSTA-1/Ocean Color Experiment (OCE) imagery

Ocean view images from the Ocean Color Experiment (OCE) were produced at three widely separated locations on the Earth. Digital computer enhancement and band ratioing techniques were applied to radiometrically corrected OCE spectral data to emphasize patterns of chlorophyll distribution and, in one shallow, clear water case, bottom topography. The chlorophyll pattern in the Yellow Sea between China and Korea was evident in a scene produced from Shuttle Orbit 24. The effects of the discharge from the Yangtze and other rivers were also observed. Two scenes from orbits 30 and 32 revealed the movement of patches of plankton in the Gulf of Cadiz. Geometrical corrections to these images permitted the existing ocean current velocities in the vicinity to be deduced. The variability in water depth over the Grand Bahama Bank was estimated by using the blue-green OCE channel. The very clear water conditions in the area caused bottom reflected sunlight to produce a sensor signal which was related inversely to the depth of the water

Lidar study of storm tops

Satellite thermal and visible observations are routinely used for storm tracking and diagnostics. In recent years attempts have also been made to apply satellite measurements to the study of evolutional factors for storms such as divergence and subsidence mechanisms. These studies involve analysis of the thermal height structure of the storm tops as obtained from the satellite observations. An outstanding problem is the importance of emissivity effects for the interpretation of the storm top thermal radiance measurements. In part to understand the correct interpretation of satellite observations, a storm top observation experiment involving advanced instrumentation on board a high altitude NASA aircraft has been in progress. A downlooking lidar system is an important part of the instrument complement. A combined analysis of the lidar return data and thermal radiance measurements was developed to study cloud top emissivity effects and their relation to satellite observations. Some preliminary conclusions are given

Vertex-Unfoldings of Simplicial Polyhedra

We present two algorithms for unfolding the surface of any polyhedron, all of whose faces are triangles, to a nonoverlapping, connected planar layout. The surface is cut only along polyhedron edges. The layout is connected, but it may have a disconnected interior: the triangles are connected at vertices, but not necessarily joined along edges.Comment: 10 pages; 7 figures; 8 reference

Critical joints in large composite aircraft structure

A program was conducted at Douglas Aircraft Company to develop the technology for critical structural joints of composite wing structure that meets design requirements for a 1990 commercial transport aircraft. The prime objective of the program was to demonstrate the ability to reliably predict the strength of large bolted composite joints. Ancillary testing of 180 specimens generated data on strength and load-deflection characteristics which provided input to the joint analysis. Load-sharing between fasteners in multirow bolted joints was computed by the nonlinear analysis program A4EJ. This program was used to predict strengths of 20 additional large subcomponents representing strips from a wing root chordwise splice. In most cases, the predictions were accurate to within a few percent of the test results. In some cases, the observed mode of failure was different than anticipated. The highlight of the subcomponent testing was the consistent ability to achieve gross-section failure strains close to 0.005. That represents a considerable improvement over the state of the art

The Long-Run Impacts of Same-Race Teachers

Black primary-school students matched to a same-race teacher perform better on standardized tests and face more favorable teacher perceptions, yet little is known about the long-run, sustained impacts of student-teacher demographic match. We show that assigning a black male to a black teacher in the third, fourth, or fifth grades significantly reduces the probability that he drops out of high school, particularly among the most economically disadvantaged black males. Exposure to at least one black teacher in grades 3-5 also increases the likelihood that persistently low-income students of both sexes aspire to attend a four-year college. These findings are robust across administrative data from two states and multiple identification strategies, including an instrumental variables strategy that exploits within-school, intertemporal variation in the proportion of black teachers, family fixed-effects models that compare siblings who attended the same school, and the random assignment of students and teachers to classrooms created by the Project STAR class-size reduction experiment

Public Support for University Funding: Trends and Determinants in Ontario, 1980-1990

This paper examines trends in public support for government funding of universities over the past decade, identifies significant social factors related to attitudes on university funding during this period, and briefly discusses possible future tendencies in public support for university funding. Growing public support for increased university funding in Ontario is documented. A variety of types of potential influences is assessed, including societal context, socio-economic status, demographic and political orientation factors. Age, educational attainment, and community size, as well as support for general government spending, are found to have significant individual-level effects on support for university funding. Multi-variate analyses suggest a growing isolation of older, less formally educated and rural people as opponents of increased university funding. The implications of these patterns in the context of an aging but increasingly educated population are then considered.Cet article examine les tendances du soutien public à l'égard des subventions gouvernementales accordées aux universités au cours des dix dernières années, identifie d'importants facteurs sociaux qui sont liés aux attitudes vis-à-vis l'attribution des fonds aux universités durant cette période, et discute brièvement des tendances éventuelles d'évolution du soutien public à l'égard des subventions accordées aux universités. On montre qu'il existe un soutienpopulaire croissant en faveur de l'augmentation des subventions accordées aux universités en Ontario. On évalue divers types d'influences possibles, y compris le contexte sociétal, le situation socio-économique, et les facteurs associés à l'orientation démographique et politique. L'âge, la scolarisation, la taille de la communauté dans laquelle on vit. ainsi que l'appui accordé aux dépenses publiques de façon générale semblent avoir des effets significatifs sur le niveau de soutien accordé au financement universitaire. Des analyses multi-variées suggèrent que les personnes plus âgés, moins scolarisées et vivant en milieux ruraux s'opposent davantage à l'augmentation des fonds accordés aux universités. On conclut en examinant les implications de ces constats dans le contexte d'une population vieillissante et de plus en plus scolarisée

New Synonomy in \u3ci\u3eHypogastrura\u3c/i\u3e (Collembola: Hypogastruridae)

(excerpt) In the course of faunistic studies of Indiana Collembola, seasonal occurrences of the two species Hypogastrura packardi (Folsom), 1902 and H. notha (MacNamara), 1922 were found to exhibit seasonal dimorphism and population dynamics similar to those patterns observed in cyclomorphic species previously reported in literature (Leinaas 1981 a,b)