Download or read book The Apparent Temperature and Emissivity of Natural Surfaces at Microwave Frequencies written by Fawwaz Tayssir Ulaby and published by . This book was released on 1970 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of surface roughness on the emissivity of natural surfaces has attained considerable importance in the fields of passive microwave remote sensing of environment and planetary surface emissions. Between the plane surface model and the Lambert surface model, which describe the two extreme cases of a perfectly flat surface and a very rough surface respectively, two statistical surface models have recently been considered: the geometric optics type surface and the physical optics type surface. The paper examines the behavior of the microwave emissivity of some natural surfaces as a function of nadir angle and polarization. This examination includes a comparison between measured and calculated values of the apparent temperature of the ocean surface at 19.4 and 37 GHz.
Download or read book Thermal Microwave Radiation written by Institution of Engineering and Technology and published by IET. This book was released on 2006-05-19 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combines theoretical concepts with experimental results on thermal microwave radiation to increase the understanding of the complex nature of terrestrial media. Emphasising on radiative transfer models, this book covers the terrestrial aspects, from clear to cloudy atmosphere, precipitation, ocean and land surfaces, vegetation, snow and ice.
Download or read book A Theory of Microwave Apparent Temperature Over the Ocean written by Shi-Tsan Wu and published by . This book was released on 1973 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Meteorological Effects on Microwave Apparent Temperatures Looking Downward Over a Smooth Sea written by Steve Wu and published by . This book was released on 1973 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of clouds and rain on microwave apparent temperatures for a flat sea surface are examined. The presence of clouds and rain can be expressed as a change of absorption coefficient and the total absorption is computed as the sum of individual effects. Various cloud and rain models proposed by meteorologists are employed to compute the microwave apparent temperature when viewing downward through these model atmospheres. It is shown that stratus, cumulus, overcast, and rain all contribute significantly to the observed temperature. Larger sensitivities to clouds and rain are observed for horizontally polarized apparent temperature at large nadir angles than for vertically polarized apparent temperature.
Download or read book Effects of Roughness on Emissivity of Natural Surfaces in the Microwave Region written by F. T. Ulaby and published by . This book was released on 1970 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of surface roughness on the emissivity of natural surfaces has attained considerable importance in the fields of passive microwave remote sensing of environment and planetary surface emissions. Between the plane surface model and the Lambert surface model, which describe the two extreme cases of a perfectly flat surface and a very rough surface respectively, two statistical surface models have recently been considered: the geometric optics type surface and the physical optics type surface. The paper examines the behavior of the microwave emissivity of some natural surfaces as a function of nadir angle and polarization. This examination includes a comparison between measured and calculated values of the apparent temperature of the ocean surface at 19.4 and 37 GHz. (Author).
Download or read book Emissivity of Natural Surfaces in the Microwave Range written by V. V. Melent'yev and published by . This book was released on 1977 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Land Surface Temperature and Microwave Emissivity from SSM I Data written by Daniel Hiltbrunner and published by . This book was released on 1996 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of an Improved Microwave Ocean Surface Emissivity Radiative Transfer Model written by Salem El-Nimri and published by . This book was released on 2010 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: An electromagnetic model is developed for predicting the microwave blackbody emission from the ocean surface over a wide range of frequencies, incidence angles, and wind vector (speed and direction) for both horizontal and vertical polarizations. This ocean surface emissivity model is intended to be incorporated into an oceanic radiative transfer model to be used for microwave radiometric applications including geophysical retrievals over oceans. The model development is based on a collection of published ocean emissivity measurements obtained from satellites, aircraft, field experiments, and laboratory measurements. This dissertation presents the details of methods used in the ocean surface emissivity model development and comparisons with current emissivity models and aircraft radiometric measurements in hurricanes. Especially, this empirically derived ocean emissivity model relates changes in vertical and horizontal polarized ocean microwave brightness temperature measurements over a wide range of observation frequencies and incidence angles to physical roughness changes in the ocean surface, which are the result of the air/sea interaction with surface winds. Of primary importance are the Stepped Frequency Microwave Radiometer (SFMR) brightness temperature measurements from hurricane flights and independent measurements of surface wind speed that are used to define empirical relationships between C-band (4-7 GHz) microwave brightness temperature and surface wind speed. By employing statistical regression techniques, we develop a physical-based ocean emissivity model with empirical coefficients that depends on geophysical parameters, such as wind speed, wind direction, sea surface temperature, and observational parameters, such as electromagnetic frequency, electromagnetic polarization, and incidence angle.
Download or read book The Response of Terrestrial Surfaces at Microwave Frequencies written by W. H. Peake and published by . This book was released on 1971 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report reviews the basic properties and terrestrial surface responses of microwave sensors, both active (radar) and passive (microwave radiometer). Appropriate surface responses (bistatic coefficient, emissivity etc.) are defined and used to provide general formulas for the system response (receiver power, antenna temperature, doppler spectrum) in terms of system geometry and configuration. The dielectric properties of terrestrial surfaces are reviewed, and data on the complex dielectric constant of rocks, soils and vegetation are tabulated. Theoretical models for surface response are provided for a variety of surface classes, including the surface of uniform layers, the surface with large scale undulation, the slightly rough surface, the surface of individual scatterers (Lommel-Seeliger surface) and the empirical models (Lambert surfaces). Finally, the report includes a large number of typical surface responses at microwave frequencies. Measured bistatic scattering coefficients, radar return, and surface brightness temperature for many terrestrial surface classes are presented and interpreted in terms of the influence of such parameters as surface roughness, dielectric constant, polarization, frequency, angle of incidence etc. on the response. (Author).
Download or read book Analytical Study of Microwave Sea Brightness Temperatures A Composite Surface Model written by and published by . This book was released on 1972 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second-order geometrical optics theory of rough surface emissivity and sea brightness temperatures is extended to lower microwave frequencies by the introduction of a composite surface model, in which the diffraction effects of surface structure smaller than a wavelength are explicitly included. Sea brightness temperatures are calculated for a range of microwave frequencies, both polarizations, all observation angles, and a variety of environmental parameters. The results are in good agreement with experiment.
Download or read book Refinement of a Semi empirical Model for the Microwave Emissivity of the Sea Surface as a Function of Wind Speed written by David Jacob Kohn and published by . This book was released on 1995 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Theory of Microwave Apparent Temperature Over the Ocean written by S. T. Wu and published by . This book was released on 1973 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the microwave region combined active (scatterometer) and passive (radiometer) remote sensors over the ocean show promise of providing surface wind speeds and weather information to the oceanographer and meteorologist. This has aroused great interest in the investigation of the scattering of waves from the sea surface. A composite surface scattering theory is investigated. The two-scale scattering theory proposed by Semyonov was specifically extended to compute the emmision and scattering characteristics of ocean surfaces. The effects of clouds and rain on the radiometer and scatterometer observations are also investigated using horizontally stratified model atmospheres with rough sea surfaces underneath. Various cloud and rain models proposed by meteorologist were employed to determine the rise in the microwave temperature when viewing downward through these model atmospheres. For heavy rain-fall rates the effects of scattering on the radiative transfer process are included.
Download or read book The Apparent Temperature of the Ocean Surface at Microwave Frequencies written by D. R. Wells and published by . This book was released on 1967 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1981 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Book Catalog of the Library and Information Services Division Subject index written by Environmental Science Information Center. Library and Information Services Division and published by . This book was released on 1977 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Remote Sensing for Environmental Sciences written by E. Schanda and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: The public's serious concern about the uncertainties and dangers of the conse quences of human activities on environmental quality demands policies to control the situation and to prevent its deterioration. But far-reaching decisions on the environmental policy are impaired or even made impossible as long as the relevant ecological relations are not sufficiently understood and large-scale quantitative information on the most important parameters is not available in sufficient quality and quantity. The techniques of remote sensing offer new ways of procuring data on natural phenomena with three main advantages - the large distance between sensor and object prevents interference with the environmental conditions to be measured, - the potentiality for large-scale and even global surveys yields a new dimension for the investigations of the environmental parameters, - the extremely wide, spectral range covered by the whole diversity of sensors discloses many properties of the environmental media not detectable within a single wave band (as e.g. the visible). These significant additions to the conventional methods of environmental studies and the particular qualification of several remote sensing methods for quantitative determination of the natural parameters makes this new investigation technique an important tool both to the scientists studying the ecological relationship and the administration in charge of the environmental planning and protection.
Download or read book Book catalog of the Library and Information Services Division written by Environmental Science Information Center. Library and Information Services Division and published by . This book was released on 1977 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
