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Electromagnetic signals propagating through the ionosphere are subject to path delay and the depolarizing effect of Faraday rotation. These are both dependent on global position and link geometry, which constantly vary for satellites in non‐geosynchronous orbits. These effects introduce performance error and reduce range resolution of remote sensing polarimetric measurements. Communication with ground...
We examine the empirical prediction of terrestrial radio link clear-air fading, and the use of parameters from surface weather stations as an alternative to, or in combination with, numerical weather prediction (NWP) reanalysis parameters. We achieve desired prediction accuracy from models employing only climatic data from surface measurements, which can be further improved with additional NWP parameters.
The next generation of wireless communications, which is proposed to operate in the mmWave region of the electromagnetic spectrum, offers the potential of high-data rate and increased coverage in response to a rapid growth of mobile data traffic. Operation in an mmWave channel is subject to physical and current technical limitations compared with conventional terrestrial microwave channel propagation...
Millimeter-waves offer the possibility of high data rate for wireless communications. With fifth generation (5G) system designers looking to combine satellite and terrestrial signals at the mobile handset, we consider the beneficial impact, using realistic system parameters, of a third orthogonal polarization at the receiver as a method of improving signal reception.
The reliable prediction of RF system performance depends on the morphology of the tropospheric environment. For instance, the performance of systems, operating at frequencies above 10 GHz, are particularly affected by hydrometeor scattering and molecular resonance processes occurring in the moist and unstable sea surface air. In addition, the turbulent transport processes occurring near the sea surface...
An electromagnetic wave propagating through the ionosphere is subject to path delay and the depolarizing effect of Faraday rotation, both of which are dependent on global position and geometry. These effects introduce error and consequently reduce the range resolution of remote sensing polarimetric measurements. Satellite-to-ground communications may be adversely altered by these effects so as to...
Terahertz frequencies offer the possibility of high resolution surveillance capabilities in areas requiring high levels of security. Terahertz imaging offers wavelengths providing high resolution with modest apertures while remaining able to penetrate clothing. In addition, they are not significantly affected by scatterers such as dust, fog and rain particles. Signal-to-noise ratio, dependent on antenna...
Millimeter-waves offer the possibility of wide bandwidth and consequently high data rate for wireless communications. For both uni- and dual-polarized systems, signals sent over a link may suffer severe degradation due to antenna misalignment. Link robustness may be enhanced by the use of mutual orthogonality in three dimensions. In the general case of a Rician fading channel the inclusion of a third...
Reliable information about the cumulative distribution of surface refractivity gradient is often required in the design of radio systems. Strong negative gradients, or super-refraction, may lead to interference between terrestrial stations, both terrestrial links and satellite earth stations. Predicted positive or sub-refractive gradients are taken into account in determining the minimum antenna heights,...
Modelling of point-to-point radio propagation over terrain is of interest in the design of radio systems working over obstructed radio paths, or which may be subject to sub-refractive fading, or in estimating the visibility of radar targets close to terrain. Practical implementation of Fourier split-step PEM to provide accurate prediction of field-strength deep into the terrain diffraction region,...
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