Noise features of the vertically propagated wave in the ionosphere

Noise is generally defined as a signal or an unwanted irregularity. Noise can come from a variety of sources and are generally random in nature. Noise is added to the signal due to noise sources when the signal is transmitted between two ends. The noise of a system is expressed by the noise factor and the noise temperature. In this study, firstly different modes of the electromagnetic wave propagating vertically in the ionosphere were theoretically solved and the reflection heights of the waves are calculated for the equinox and solstice days of 2015 (21 March-21 June-23 September-21 December), local time 12:00 and frequencies of 3,4,5,6 MHz. The noise temperature values for these modes and frequencies were then calculated and the results compared. Key Words: Ionosphere, Electromagnetic Wave, Noise Temperature