Profilers/Sounders
DIGISONDES
Ionosondes and Digisondes are devices that send a spectrum of radio wave pulses straight up (vertically incident to the ground). They measure the length of time it takes for a reflection to be returned, the strength of the reflection, and how high of a frequency can be reflected. From these three data points (time, strength, frequency), the device can determine ionization density, altitude of the ionization, and potential Maximum Useable Frequency (MUF). Output from ionosondes and digisondes are displayed in the form of an "ionogram", or displayed in a tabular data format Additional information available at "http://www.amfmdx.net/fmdx/ionosonde.html"