Comparison of scintillation measurements from a 5 km communication link to standard statistical models

Abstract

As part of a free-space optical communications experiment over a 5km horizontal path, an extensive database of tilt-stabilized receiver data was collected for C 2 n conditions ranging from benign to very strong. This paper focuses on the scintillation measurements made during those tests. Ensemble probability distributions are compiled from these results, and are subsequently compared with standard channel models such as the log-normal and gammagamma distributions. Statistical representations of temporal behavior are also developed from this database. Accurate statistical models of atmospheric channel effects have proved to be invaluable in the development of high-performance free-space transceivers.

Comparison of probability density functions for analyzing irradiance statistics due to atmospheric turbulence

“…Mahon et al [35] applied the GG PDF to perform an unconstrained fit of their irradiance data by using a proposed relationship between the fitting parameters and the SI. The fitting parameters of the GG PDF were inferred from experimental measurements by Vetelino et al [11], but a least-squares fitting approach similar to that used by Michael et al [36], was used here. Attempts have been made to relate the fitting parameters of the IK PDF to the Rytov variance of a plane wave in both weak and strong turbulence regimes [15].…”

Performance and qualification of a multi-rate DPSK modem

“…We generate representative fade profiles from a model 13,14 and use a digitalto-analog converter to take the calculated time-series and convert it to an analog waveform. This is then used to drive a fast (MHz-class) variable optical attenuator to impose an optical fading profile.…”

Performance of a FSO augmented RF mesh network

“…The gamma-gamma model of irradiance distribution has been shown to be valid in all regimes of optical turbulence. [5][6] Unlike other models, such as the lognormal, the gamma-gamma model is based upon developments in scintillation theory which model the received irradiance as a modulation process of both small-scale and large-scale fluctuations. In measuring irradiance statistics, the most important, yet difficult task is accurately measuring intensity levels as low as 50 dB below the mean.…”