HF ground-wave propagation
A Mathematical Model of Multi Hop HF Radio Propagation
... mHz). HF ra- dio waves from the ground whose frequencies are under maximum usable fre- quency (MUF) travel further and further with each successive hop by the reflec- tions between the earth and the ...
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Basics of Radio Wave Propagation
... lower HF bands, aerials tend to be close to the ground (in terms of ...direct wave and reflected wave tend to cancel each other out (there is a 180 degree phase shift on ...
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Radio Propagation Prediction for HF Communications
... reasons, HF propagation is basically split into skywave, groundwave and near vertical incidence ...Groundwave propagation is used for relatively short links over a few tens of kilometres whereas ...
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Ultrasonic wave propagation in powders
... The aim of this paper is to investigate the feasibility of using ultrasonic techniques to monitor powder caking. The theory of ultrasonic wave propagation in powder will be discussed. Two ultrasonic ...
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Wave propagation in granular materials
... Two strain-gauge pressure transducers (Honeywell AB/HP ABH006PGC1B: 0-6 psi, 1.9 cm active face) are buried in the bed at the same depth but at different distances from the piston. The near transducer is typically placed ...
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Wave propagation in an inhomogeneous medium
... further away from the axis takes less time to travel from source to receiver than sound energy traveling closer to the axis,.. of sound energy in the sound channel at certain ranges.[r] ...
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HF wave propagation and induced ionospheric turbulence in the magnetic equatorial region
... (EM) wave and extending horizontally along the magnetic fi eld lines due to Ohmic heating of the plasma, as well as creation of a virtual antenna at ULF/ELF/VLF frequencies by modulation of the D/E conductivity of ...
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Wave and tidal power measurement using HF radar
... tions. Wave buoys and ADCPs provide very useful information for these applications but, unless they are deployed in large numbers, cannot provide information about spatial ...[1] HF radars can provide ...
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Atmospheric Millimetre Wave Propagation.
... Amplitude scintillations of millimetre radio waves depend on the fluctuations of the atmospheric refractive index which in turn has a time dependence which is a [r] ...
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Effect of Partial Ground Plane Removal on the Radiation Characteristics of a Microstrip Antenna
... finite ground plane, surface waves propagate until they reach an edge where they reflected back and diffracted by the ...surface wave diffraction from the edges of the antenna ground ...surface ...
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New Method in Calculating the Trajectory of Sound Waves at Stratified Ocean
... reflected wave, [5], considering that its amplitude V at small gradients of sound speed in waveguides is much smaller than the amplitude of the transmitted wave ...During propagation resulting re- ...
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Ground Clearance for HF and Lower Frequency Antenna Installations
... up ground based antennas for operation in the HF and longer wavelength bands frequently involves clearing large areas of land for the installation of ground mats to provide a high conductivity return ...
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Wave propogation scattering due to defect on thin composite plates
... propagating wave propagation through an existing damage on composite ...propagating wave that started from any source will vary when crossing an area with ...frequency wave propagation ...
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Wave Propagation in Nanocomposite Materials
... Electromagnetic wave propagation is first analyzed in a composite material mde of chiral nano-inclusions embedded in a dielectric, with the help of Maxwell-Garnett formula for permittivity and permeability ...
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Reconfigurable antennas and radio wave propagation at millimeter-wave frequencies
... Next, the performance of the conformal antenna arrays is investigated. The characteristics of the developed antenna prototypes are validated by the measurements using a probe fed antenna measurement system. The radiation ...
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Influence of tidal sand wave fields on wind wave propagation
... sand wave fields on wind ...wind wave amplitude and the corresponding near-bed orbital flow velocities inside the ...sand wave crests were orientated perpendicular to the wind wave ...sand ...
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Electromagnetic Wave Propagation into Fresh Water
... multipath propagation. Also, the channel latency caused by the low propagation velocity in water is an- other limitation of acoustic ...higher propagation speed than underwater acoustic ...
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Influence of high latitude anomalies on tropical climate phenomena and global climate
... Analysis of the energy budget has clarified the mechanism. The increase in salinity caused by the anomaly drives deep convective overturning in the Weddell Sea and Drake Passage, creating strong kinetic and potential ...
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Effect Of Terrain Features On Wave Propagation
... Path-loss prediction algorithms for advanced wireless communication system planning have long considered the effect of electromagnetic propagation over buildings between the base station and subscriber. It briefly ...
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Directional spectra comparisons between HF radar and a wave model
... Wyatt, L.R., Green, J.J. and Middleditch, A. (2008) Directional spectra comparisons between HF radar and a wave model. In: Proceedings of the IEEE/OES/CMTC 9th working conference on Current Measurement ...
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