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Use of Rare Earth Materials in mm-Wave Microwave Systems and Sensors
Published in A. R. Jha, Deployment of Rare Earth Materials in Microware Devices, RF Transmitters, and Laser Systems, 2019
For precision system design it is desirable to use the standard radiometric temperatures as a function of surface conditions under clear and moderate rain conditions. It is important to mention that the radiometric temperature of a surface consists of a thermally emitted power component (PƐ) and a reflected power component (Pre). It should be stressed that the emissivity (Ɛ) of a surface is defined as the ratio of surface brightness temperature to the brightness temperature of a blackbody at the same physical (kinetic) temperature. In addition, the emissivity is strictly a function of the aspect angle and the apparent radiometric temperature of a surface also depends on the aspect angle, which is also known as grazing angle or depression angle. Typical 95-GHz radiometric temperatures as a function of background surfaces under clear and moderate rain conditions are summarized in Table 6.8[5].
Passive Imaging
Published in Iain H. Woodhouse, Introduction to Microwave Remote Sensing, 2006
The basic principle of ocean measurements is that the surface term, TSURF, in (8.1) is a function of two of the three important properties that govern the physical attributes of the oceans: namely the temperature and the salinity, the density being the third property (but this does not influence the brightness temperature). In Chapter 5 we saw that temperature is positively correlated with emissivity across the entire microwave region of the spectrum, whereas salinity influences the emissivity significantly only at long microwave wavelengths (<6 GHz). Brightness temperature is directly related to the physical temperature times the emissivity. Additionally, since the atmospheric attenuation is low for microwaves, and hydrometeors have a decreasing influence for lower frequencies, then measurements can be acquired even when there is cloud cover.
Radio Thermal Radiation
Published in N.A. Armand, V.M. Polykov, Radio Propagation and Remote Sensing of the Environment, 2004
The black-body reflective coefficient is equal to zero and, in this case, the brightness temperature is simply equal to the temperature of the black body. So, the brightness temperature is the temperature of a black body at which it radiates with the same intensity as the heated body at a given polarization and frequency. In the example discussed here, the following value is the emissivity (coefficient of emission): () κ(ω)=1−|F(0)|2
COVID-19 lockdown effect on land surface temperature and normalized difference vegetation index
Published in Geomatics, Natural Hazards and Risk, 2021
Equations (11–12) computes the internal parameters and and Eq. (13) retrieves LST from OLI/TIRS data (Qin et al. 2001): where = land surface emissivity, = total atmospheric transmittance, and are internal parameters based on atmospheric transmittance and land surface emissivity, = land surface temperature, = mean atmospheric temperature, = at-sensor brightness temperature,
Urban growth nexus to land surface temperature in Ghana
Published in Cogent Engineering, 2022
Samuel Kwofie, Clement Nyamekye, Linda Appiah Boamah, Frank Owusu Adjei, Richard Arthur, Emmanuel Agyapong
The methods for calculating LST from Landsat data have been extensively used in various research. The first step is converting DNs of the thermal bands (i.e., bands 10 and 11 in Landsat-8) to absolute units of at-sensor spectral radiance (Li, song et al., 2011; Weng, 2009; Chander et al., 200). Second, the thermal band data is converted from at-sensor spectral radiance to effective at-sensor brightness temperature, under the assumption that the Earth’s surface is a black body (i.e., spectral emissivity = 1) using Equation (1; Chander et al., 2009; USGS(USGS (United States Geological Survey), 2016).
Analytical study on the relationship between land surface temperature and land use/land cover indices
Published in Annals of GIS, 2020
Subhanil Guha, Himanshu Govil, Neetu Gill, Anindita Dey
where, is the land surface emissivity, is the total atmospheric transmittance, is the at-sensor brightness temperature, is the mean atmospheric temperature, is the near-surface air temperature, is the land surface temperature, ,.