Estimation of the Cumulative Amplitude Probability Distribution Function of Ionospheric Scintillations.
Abstract:
The fading characteristics of ionospheric scintillations can be precisely described by a cumulative amplitude probability distribution function cdf. The cdf expresses the probability or percentage of time that the signal amplitude will equal or exceed a given amplitude. Utilizing ionospheric scintillations observed on beacon signals from synchronous satellites transmitting at 136 MHz, distributions of amplitude variations have been made. The resulting distributions have been divided into five groups corresponding to ranges of scintillation index, the predominant measure in scintillation studies. The five distribution models are then combined with the occurrence of scintillations in various index ranges to produce cumulative amplitude probability distributions. These have been done for long term observations made at Hamilton, Mass., Narssarssuaq, Greenland, and Huancayo, Peru. The resulting data allows engineers to determine margins necessary for communication and navigation systems. Author