|
|
Very Low Frequency The very low frequency spectrum (3 to 30 kHz) may be used to monitor sudden ionospheric disturbances (SID) caused by solar flares. The VLF receiver is tuned to a VLF transmitter 700 or more kilometers away. The transmitted signals propagate by an ionosphere-Earth waveguide mode. The Sun's radiation during a solar flare affects the Earth's ionosphere in such a way that VLF propagation is enhanced. This appears on the receiver output as an increase in signal level that has a characteristic shape. Click here for a VLF Receiver System that at one time we sold in kit form. |
|
|