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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 ...
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.
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]
Radio wave propagation is affected by atmospheric conditions, ionospheric absorption, and the presence of obstructions, for example mountains or trees. Simple formulas that include the effect of the atmosphere give the range as:
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 ...
In radar satellites, microwave signals are reflected off a persistent scatter in a target area, and their two-way travel time is measured by satellites. [1] Water vapor in the troposphere and free electrons in the ionosphere affect the propagation of microwave signals through the atmosphere because the different refractive index in these layers affects the speed of propagation.
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An ionospheric heater, or an ionospheric HF pump facility, is a powerful radio wave transmitter with an array of antennas which is used for research of plasma turbulence, the ionosphere and upper atmosphere.