#RADIO AND RECEIVER CIRCUIT PHYSICS 101 FREE#

Ionization depends primarily on the Sun and its activity. This again means that the ionosphere is ‘produced’ during the day and is ‘reduced’ during the night due to recombination processes of electrons and ions. However, the charged nature of the ionosphere is due to production of plasma (electrons, ions) primarily by solar ultraviolet radiation. The main constituents of the ionosphere are neutral atoms and molecules. One may see the the ionosphere as a shell of electrons and electrically charged ions (atoms and molecules) that surrounds the Earth, stretching from a height of about 60 km to more than 1000 km.

To understand the SID effect it is essential to remember how Earths’ ionosphere is created and structured. Scientists on the ground can use this enhancement to detect solar flares by monitoring the signal strength of a distant VLF transmitter, sudden ionospheric disturbances ( SID) are recorded and indicate when solar x-ray flares have taken place. The ionospheric disturbance enhances VLF radio propagation. The low altitude ionospheric layers ( D and E region) immediately increase in density over the entire day-side.

#RADIO AND RECEIVER CIRCUIT PHYSICS 101 FREE#

This high energy radiation is absorbed by atmospheric particles, raising them to excited states and knocking electrons free in the process of photo-ionization. When a solar flare occurs on Sun a blast of intense ultraviolet and x-ray radiation hits the day-side of the Earth after a propagation time of about 8 minutes. In our system we used the VLF receiver proposed by the UKRAA (UK Radio Astronomy Association). SID events heavily modify the ionosphere and therefore can be detected by measuring, over time, the intensity of radio propagation in the VLF band. Monitoring SID events is therefore an indirect way to monitor solar activity. As is well known, SID events are caused by the impact with the ionosphere of solar radiation emitted during solar flares. Abstract : in this post we present a system for monitoring sudden ionospheric disturbances (SID) events.

Radio and receiver circuit physics 101