Editing Ionospheric sounding

{{Short description|Radio technique}}
{{inline|date=January 2017}}

In [[telecommunications]] and [[radio science]], an '''ionospheric sounding''' is a technique that provides real-time [[data]] on [[high-frequency]] ionospheric-dependent [[radio propagation]], using a basic [[system]] consisting of a synchronized transmitter and receiver. 

The time [[Propagation delay|delay]] between [[transmission (telecommunications)|transmission]] and reception is translated into effective [[ionospheric layer]] altitude. Vertical incident sounding uses a collocated transmitter and receiver and involves directing a range of frequencies vertically to the [[ionosphere]] and measuring the values of the reflected returned signals to determine the effective ionosphere layer altitude. This technique is also used to determine the [[critical frequency]]. Oblique sounders use a transmitter at one end of a given propagation path, and a synchronized receiver, usually with an oscilloscope-type display ([[ionogram]]), at the other end. The transmitter emits a stepped- or swept-[[frequency]] [[signal]] which is displayed or measured at the receiver. The measurement converts [[time]] delay to effective altitude of the ionospheric layer. The ionogram display shows the effective altitude of the ionospheric layer as a function of frequency.

==See also==
*[[Kennelly–Heaviside layer]]
*[[Edward V. Appleton]]

==References==
*{{FS1037C}}

[[Category:Ionosphere]]
[[Category:Radio frequency propagation]]


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