http://www.suntrek.org/sun-earth-connection/what-is-space-weather/space-weather-affect/radio-communication.shtml
Pretty sure that you need to shoot the radio signal at a low angle for it to be mostly reflected off the ionosphere
http://www.suntrek.org/sun-earth-connection/what-is-space-weather/space-weather-affect/radio-communication.shtml
Pretty sure that you need to shoot the radio signal at a low angle for it to be mostly reflected off the ionosphere