Statistical and temporal irradiance fluctuations modeling for a ground-to-geostationary satellite optical link

Abstract

An optical communication link performance between the ground and a geostationary satellite can be impaired by scintillation, beam wandering, and beam spreading due to its propagation through atmospheric turbulence. These effects on the link performance can be mitigated by tracking and error correction codes coupled with interleaving. Precise numerical tools capable of describing the irradiance fluctuations statistically and of creating an irradiance time series are needed to characterize the benefits of these techniques and optimize them. The wave optics propagation methods have proven their capability of modeling the effects of atmospheric turbulence on a beam, but these are known to be computationally intensive. We present an analytical-numerical model which provides good results on the probability density functions of irradiance fluctuations as well as a time series with an important saving of time and computational resources.

Statistical evaluation of the performance of free-space-optical link affected by optical turbulence with gamma-gamma distribution through time series generated by simulation

“…The SNR0 value was considered constant (i.e., 10 dB), which is related to Eq. (14). Figure 11 shows the block diagram used in order to obtain the simulation results considering particular values for the different subsystems of the overall communication system.…”

“…Although there are some experimental proposals for atmospheric turbulence chambers, they present important limitations and trade-offs such as 1) static or sometimes dynamic design with reduced configuration parameters, 2) reduced limit of emulated link distances, and 3) re-duced control of atmospheric turbulence levels, among others [9,10]. Several mathematical algorithms simulate the effects of atmospheric turbulence over an optical field [11][12][13][14]. However, to the best of our knowledge, such algorithms do not determine the actual received optical power (measured in Watts) for the different possible regimes of atmospheric turbulence based on characteristics of physical devices.…”

Atmospheric turbulence characterization using a neuromorphic camera-based imaging sensor

“…Another difference is that the events can be triggered not only by displacement of image features (similar to focal spot wander), but also via increase or decrease of the features' brightness. Some other factors such as turbulence inhomogeneities along the imaging path and the impact of turbulence outer-scale [15,16] may also affect the measurement with respect to the applicability of equation (2) in describing event span characteristics.…”

Numerical prediction and experimental validation of irradiance fluctuations in a pre-compensated optical feeder link

“…The use of adaptive optics in optical ground stations for high-rate optical links from space to ground is state of the art 1,2 . The adaptive pre-compensation of the transmitted wave-front is considered an enabling technology for high-rate optical data transmission from ground to space, and subject to extensive researchboth analytically, and experimentally 3,4,5,6,7 .…”

“…In order to properly size the system, we want to predict the performance of the pre-compensation, under various atmospheric conditions, for different link geometries, and for varying key system parameters (such as beam diameter). To this end, we developed a multiple-phase-screen propagation model, similar to models already published 7 . In Section 2, we present the key features of the model, the parameter set we chose for the realistic worst case in an optical ground-to-GEO uplink (driving the system design), and some validation results.…”