8,986 research outputs found
Analyses of earth radiation budget data from unrestricted broadband radiometers on the ESSA 7 satellite
Six months of data from the wide-field-of-view low resolution infrared radiometers on the Environmental Science Services Administration (ESSA) 7 satellite were analyzed. Earth emitted and earth reflected irradiances were computed at satellite altitude using data from a new in-flight calibration technique. Flux densitites and albedos were computed for the top of the earth's atmosphere. Monthly averages of these quantities over 100 latitude zones, each hemisphere, and the globe are presented for each month analyzed, and global distributions are presented for typical months. Emitted flux densities are generally lower and albedos higher than those of previous studies. This may be due, in part, to the fact that the ESSA 7 satellite was in a 3 p.m. Sun-synchronous orbit and some of the comparison data were obtained from satellites in 12 noon sun-synchronous orbits. The ESSA 7 detectors seem to smooth out spatial flux density variations more than scanning radiometers or wide-field-of-view fixed-plate detectors. Significant longitudinal and latitudinal variations of emitted flux density and albedo were identified in the tropics in a zone extending about + or - 25 deg in latitude
Laser Doppler technology applied to atmospheric environmental operating problems
Carbon dioxide laser Doppler ground wind data were very favorably compared with data from standard anemometers. As a result of these measurements, two breadboard systems were developed for taking research data: a continuous wave velocimeter and a pulsed Doppler system. The scanning continuous wave laser Doppler velocimeter developed for detecting, tracking and measuring aircraft wake vortices was successfully tested at an airport where it located vortices to an accuracy of 3 meters at a range of 150 meters. The airborne pulsed laser Doppler system was developed to detect and measure clear air turbulence (CAT). This system was tested aboard an aircraft, but jet stream CAT was not encountered. However, low altitude turbulence in cumulus clouds near a mountain range was detected by the system and encountered by the aircraft at the predicted time
Dynamic Correlation in Wave Propagation in Random Media
We report time-resolved measurements of the statistics of pulsed transmission
through quasi-one-dimensional dielectric media with static disorder. The
normalized intensity correlation function with displacement and polarization
rotation for an incident pulse of linewidth at delay time t is a
function only of the field correlation function, which is identical to that
found for steady-state excitation, and of , the residual
degree of intensity correlation at points at which the field correlation
function vanishes. The dynamic probability distribution of normalized intensity
depends only upon . Steady-state statistics are recovered
in the limit ->0, in which is the steady-state
degree of correlation.Comment: 4 RevTex pages, 4 figure
Grasslands of the Great Plains: Their Nature and Use
This book is the result of a long-felt need by the authors and their students for a comprehensive survey of the numerous studies that have been made on plains grasslands. From southern Texas far into Saskatchewan the mid and short grasses form a magnificent prairie nearly 2,500 miles in length and approximately 400 miles wide. Kinds of communities, their composition, nature, significance and uses are fully described. Such information is of value not only to students, range technicians, and other professional conservationists, but also to ranchers and other land owners-in fact, to anyone interested in the economy of our midwestern grasslands. The damaging effects of drought on forage production in this unstable climate and the restoration of the plant cover are of such great importance that they have been given special attention. Climate, soils, and. the proper use of the forage for its sustained production are described.
A third of a century of study and experimentation in plains grassland by the authors permits accurate description and interpretation. Important studies that have been made on the vegetation since the coming of the white man to the present day are reviewed. Early investigations have been recorded in papers, bulletins and books, many of which are now out of print or difficult of access. Therefore permission was asked and promptly given by the Carnegie Institution of Washington, Duke University Press, Ecological Monographs, Ecology, and several other journals to re-use materials originally furnished by the authors. Such sources are carefully cited in the text. Only by such cooperation has this book been made possible.
This great prairie land has been thoroughly examined as to its way of life both above ground and deep into the soil, which it has helped to build and so efficiently protects. Extensive, long-time investigations have elucidated many problems. The scope of the work has been broadened and deepened by the aid of a large number of advanced students who have sought graduate study in this field. To them, many of whom are today leaders in conservation of range management or in teaching a new generation of students the values of ecology in our economy, we are deeply grateful for their interest and cooperation. Two of them are so familiar with the grasslands of Texas and New Mexico, respectively, that each has contributed a chapter to this book.
Both common and scientific names of grasses are according to Hitchcock and Chase (1950) revised Manual of the Grasses of the United States. Other scientific names follow Gleason\u27s New Britton and Brown Illustrated Flora (1952) or Harrington\u27s Manual of the Plants of Colorado (1954). Common names are nearly all according to the second edition (1913) of Britton and Brown or the second edition of Standardized Plant Names (1942).
404 page
Failure of the ERBE scanner instrument aboard NOAA 10 spacecraft and results of failure analysis
The Earth Radiation Budget Experiment (ERBE) scanner instrument on the NOAA 10 spacecraft malfunctioned on May 22, 1989, after more than 4 years of in-flight operation. After the failure, all instrument operational mode commands were tested and the resulting data analyzed. Details of the tests and analysis of output data are discussed therein. The radiometric and housekeeping data appear to be valid. However, the instrument will not correctly execute operational scan mode commands or the preprogrammed calibration sequences. The data indicate the problem is the result of a failure in the internal address decoding circuity in one of the ROM (read only memory) chips of the instrument computer
The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
We present the final data release of observations of lambda 21-cm emission
from Galactic neutral hydrogen over the entire sky, merging the
Leiden/Dwingeloo Survey (LDS: Hartmann & Burton, 1997) of the sky north of
delta = -30 deg with the Instituto Argentino de Radioastronomia Survey (IAR:
Arnal et al., 2000, and Bajaja et al., 2005) of the sky south of delta = -25
deg. The angular resolution of the combined material is HPBW ~ 0.6 deg. The LSR
velocity coverage spans the interval -450 km/s to +400 km/s, at a resolution of
1.3 km/s. The data were corrected for stray radiation at the Institute for
Radioastronomy of the University of Bonn, refining the original correction
applied to the LDS. The rms brightness-temperature noise of the merged database
is 0.07 - 0.09 K. Residual errors in the profile wings due to defects in the
correction for stray radiation are for most of the data below a level of 20 -
40 mK. It would be necessary to construct a telescope with a main beam
efficiency of eta_{MB} > 99% to achieve the same accuracy. The merged and
refined material entering the LAB Survey of Galactic HI is intended to be a
general resource useful to a wide range of studies of the physical and
structural characteristices of the Galactic interstellar environment. The LAB
Survey is the most sensitive Milky Way HI survey to date, with the most
extensive coverage both spatially and kinematically.Comment: 9 pages, 5 figures, accepted for publication by Astronomy &
Astrophysic
- …