Probability density function of amplitude scintillations

The letter reports on amplitude scintillation measurements of the orbital test satellite (OTS) BO carrier beacon carried out from June to December 1983. The scintillations are here characterized by standard deviations of the amplitude fluctuations and by the distribution of amplitude deviations from their mean. It is known that during scintillations log-amplitudes are normally distributed for short time intervals (1 min). The long-term probability density of amplitude scintillations can be calculated using recorded 1 min standard deviations sigma. The probability density function of log (/sigma - sigma-N//dB) can be well approximated by a Gaussian distribution, where sigma-N is the 1 min standard deviation due to thermal noise alone.