Analysis of Probability Density Function Models

doi:10.1117/3.2643989.ch5

Book: Laser Beam Propagation in Random Media: New and Advanced Topics

Author(s): Larry C. Andrews, Melissa K. Beason

Published: 2023

https://doi.org/10.1117/3.2643989.ch5

Author Affiliations +

Abstract

The reliability of a free-space optical communications (FSOC) system in atmospheric turbulence can be deduced from a mathematical model of the probability density function (PDF) of the irradiance (also called intensity). Scintillation can lead to power losses at the pupil plane of a receiver (Rx) and eventually to fading of the received signal below a specified threshold in the detector plane. Consequently, one of the goals in studying optical wave propagation through the atmosphere is the identification of a tractable PDF model for the irradiance under all irradiance fluctuation conditions. Over the years, an abundance of PDF models has been proposed with varying degrees of success. Of particular importance are (1) the accuracy of the PDF model in the low-intensity portion of the tail that leads to the probability of fade and (2) the bit error rate in the design of FSOC systems. Accuracy in the high-intensity portion of the tail is also important for eye-safety calculations and to recognize the potential for equipment damage through random surges.