There exists a way of generating a dopplergram of the Ionosphere, using a radio and soundcard software, which allow you to look at the Ionosphere, with nothing more than a computer, radio…. You can see the various changes to the Ionosphere, and learn things! A fun combination. A Dopplergram uses an existing radio transmitter, (like WWV), and then monitors very small Doppler shifts in the signal. Shifts as low a .25 Hz, can be seen and graphed.
For a general overview of Dopplergrams visit ZL1PBU’s page. You will need a piece of software to chart the received frequency vs. time. A good place to discuss your Dopplergrams and get the software SBSpectrum is on the Yahoo group for Dopplergrams.
Below you will find a Dopplergram showing two solar flares
Note the two Solar flares at 1958, and 2105. This was taken using WWV 10 MHz., as the source, and watching the Doppler shift of the Ionosphere. At 2150, you can see an E/F layer split begin, this is as evening approaches at my QTH, so it is to be expected. On other Dopplergrams, I have seen both E and F layer propagation continue all night. All in all, this is a fairly useful tool for propagation study.