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Showing 1 to 9 of 9 for “"radiowave propagation"”.
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Extraction of Input Parameters for the Theory of Radiative Energy Transfer Using Deconvolution.
… requires accurate models for characterising radiowave propagation when affected by the presence of a variety of obstacles. In particular if the obstacles take the shape of vegetation volumes, like single trees or groups of trees and are present in the radio path, they give rise to absorption …
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ΣΥΜΒΟΛΗ ΣΤΗ ΜΕΛΕΤΗ ΤΗΣ ΕΠΙΔΡΑΣΗΣ ΤΗΣ ΑΤΜΟΣΦΑΙΡΙΚΗΣ ΔΙΑΘΛΑΣΗΣ ΚΑΤΑ ΤΗ ΧΡΗΣΗ ΡΑΔΙΟΚΥΜΑΤΩΝ ΣΤΙΣ ΣΥΓΧΡΟΝΕΣ ΓΕΩΔΑΙΤΙΚΕΣ ΜΕΘΟΔΟΥΣ ΜΕΤΡΗΣΕΩΝ ΜΕΓΑΛΩΝ ΑΠΟΣΤΑΣΕΩΝ
THE THREE MAIN EFFECTS OF THE ATMOSPHERE ON RADIOWAVE PROPAGATION ARE: ATTENUATION, TIME DELAY AND ANGULAR BENDING. THE TIME DELAY CAN BE SEPARATED INTO HYDROSTATIC AND WET DELAY. DEVELOPED HERE ARE MODELS FOR THE ZENTH WET DELAY ESTIMATION AND FOR THE ELEVATION DEPENDENCE OF THE HYDROSTATIC AND …
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Improvements to the modelling of radiowave propagation at millimetre wavelengths. In-depth studies are reported on resonance phenomena in the scattering of spherical ice particles, extinction and backscattering properties of clouds and on the absorption and dispersion spectra of atmospheric gases.
Various physical mechanisms that affect radiowave propagation at millimetre wavelengths are considered. Current modelling weaknesses are highlighted and new improved models or more appropriate modelling approaches are suggested. Interference and resonance phenomena in the scattering of spherical …
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Radio Characterisation of Single Trees at Micro- and Millimetre Wave Frequencies
… design and implementation on the availability of radiowave propagation models. These models are required to describe and characterise with sufficient accuracy the interaction of radiowaves with the environment, especially the various obstacles in the radio path. Prediction tools are highly …
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Modelling and Measurement of the Scatter of Microwaves by Buildings
… recommendations for building scatter effects in radiowave propagation. The work has also contributed regularly to the technical output of European COST project 235.<br/>
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A discrete RET Model for Micro- and Millimetre Wave Propagation through Vegetation
… design and implementation on the availability of radiowave propagation models. In the particular case of land mobile radio systems and wireless fixed access systems, obstacles in the form of vegetation volumes, e.g formations of trees, are likely to influence radio propagation, giving rise to …
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Characterization and Modeling of Solar Flare Effects in the Ionosphere Observed by HF Instruments
… trans-ionospheric high frequency (HF, 3-30 MHz) radiowave propagation. Solar activities, such as solar flares, radiation storms, coronal mass ejections (CMEs), alter the state of the ionosphere, a phenomenon known as Sudden Ionospheric Disturbance (SID), that can severely disrupt HF radio …
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Wideband Terrestrial Path Loss Measurement Results For Characterization of Pico-cell Radio Links at 38 GHz and 60 GHz Bands of Frequencies
… equipment setup, and calibration procedures for propagation measurement campaigns. Power Delay Profile (PDP) snapshots recorded during measurement campaigns are thoroughly analyzed using the 'Channel Imaging Analysis Suite' and Path Loss as well as Rain Attenuation statistics, calculated from …