When I first started looking at radio astronomy I kept hearing about Super Sid. I had heard of Superman but not Super Sid, so who is he? Turns out superSID is a way of monitoring solar activity. SID stands for Sudden Ionospheric Disturbances, and a superSID monitor is used to look for these disturbances as well as SES’s, Sudden Enhancement of Signals.
The ionosphere is the part of the earths upper atmosphere ionised by the sun. Stretching from 37 miles up to 620 miles it takes in the thermosphere, mesosphere and exosphere, and makes up the inner edge of the magnetosphere. The ionosphere is important for radio transmissions as signals can be bounced off the ionosphere.
Radio waves, as electromagnetic transmissions, travel in a straight line. Since the earth is a sphere, radio waves cannot travel round the earth without being reflected. Satellites perform this function for some wavelengths whilst other wavelengths reflect off the ionosphere.
Signals reflected off the ionosphere can be detected with a 1.65 metre hexagonal loop antenna, though being typically less than 0.1 millivolts the signals will need a PreAmp to magnify them. A HD sound card captures the signal and converts it from analog to digital. A computer program then reads the data and measures its strength in the form of spikes. If the strength of the data changes throughout the day, with bigger spikes, this could indicate a solar flare from the sun.
VHF radio waves at a frequency of 3-30kHz are affected by disturbances in the ionosphere, in the D,E,F layers. Intense bursts of X-rays increases ionisation dropping radio reflection to a lower layer, this is read as a spike on the monitor.
Some organisations distribute superSID monitors to appropriate community centres such as schools and universities, from which they collect the data. One such organisation is Stanford Solar Centre in California, USA. They have a partnership with the US Society of Amateur Radio Astronomers to collect this data.
Data received from multiple superSID sources helps monitor activity on the suns surface. We can predict atmospheric changes which affect communication transmissions such as mobile phones, radio and GPS.