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An ionospheric model is a mathematical description of the ionosphere as a function of location, altitude, day of year, phase of the sunspot cycle and geomagnetic activity. Geophysically, the state of the ionospheric plasma may be described by four parameters: electron density, electron and ion temperature and, since several species of ions are ...
A height of 1.4 km from the ground surface contains 50% of the water vapor mass, and both on the global and local scales, most of the world's weather takes place in this layer. [4] Therefore, the tropospheric path delays are caused by differences in temperature, atmospheric pressure, and the water vapor in the lower part of the atmosphere ...
The model can represent variation of these quantities with altitude, latitude, longitude, date, and time of day. It can also make use of solar, ionospheric and geomagnetic indices to refine the model. Vertical total electron content (TEC) may be derived. (A snapshot of model predictions is shown in the latitude vs. longitude map above). [6]
In radio communication, multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial objects such as mountains and buildings.
The signal transmitted from the satellite to the receiver crosses the ionospheric shell in the so-called ionospheric pierce point (IPP). The zenith angle at the IPP is z' and the signal arrives at the receiver with zenith angle z. Here R is the mean Earth radius, H is the mean height of the ionosphere shell.
Skywave propagation on the sunlit side of the Earth can be entirely disrupted during sudden ionospheric disturbances. Because the lower-altitude layers (the E-layer in particular) of the ionosphere largely disappear at night, the refractive layer of the ionosphere is much higher above the surface of the Earth at night. This leads to an increase ...
The 3105-kilocycle frequency, thanks to ionospheric refraction, can broadcast on multiples, or harmonics, of that frequency. Harmonics, in turn, can skip for thousands of miles.
Rain falling over a drainage basin in Scotland.Understanding the cycling of water into, through, and out of catchments is a key element of hydrology. Hydrology (from Ancient Greek ὕδωρ (húdōr) 'water' and -λογία () 'study of') is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and ...