Probability density distribution of wideband 2-6 MHz terrestrial radio noise

The probability distribution of terrestrial noise and interference was measured in 50-KHz bandwidths in the 2-6 MHz range before and after signal processing for noise reduction. By excising both impulsive noise bursts and narrowband interference (117-Hz resolution bands), signal processing can lower the high-noise tail of the distribution by 25-35 dB at the first percentile. After excising, the sensitivity of detection is then correspondingly improved, approaching to within 5-8 dB of the sensitivity achieved in Gaussian noise of the same power level.