A Method Based on Amplitude Probability Density Representation for Sounding High Frequency Noise in Ionospheric Channels

High Frequency (HF) communications efficiency require a precise characterization of the ionospheric channel’s noise. We present a rapid and accurate method to sound the HF ionospheric channels that enables tracing of the time-availability of the channel based on imposed electric field strength thresholds. The method makes use of the amplitude probability density implemented in a real-time spectrum analyzer. Sounding of 3, 10 and 20 kHz bandwidth channels in the 4.8 – 8.8 MHz range is exemplified and specific observations are presented.