Study on Fog Attenuation Characteristics and Experiment Measurement for Laser Propagation in Atmosphere

Abstract

The availability of atmosphere laser communication systems in dependence on weather conditions and on atmosphere laser link parameters, such as transmitted optical power, beam divergence, or link path distance, is discussed. A number of phenomena in the atmosphere, such as fog, can affect beam attenuation. In this work, the analysis and simulation of the empirical models (like Kruse, Vasseur, etc) indicate that the predicted attenuation of those models is similar and the main attenuation factor of 532nm laser propagation in atmosphere is aerosol particle. Attenuation caused by fog, which can be expressed as a function of the link distance, wavelength, and meteorological visibility, is calculated from visibility data collected at several locations in Guilin. Statistical evaluation of the attenuation caused by fog and the power link margin calculated from atmosphere laser communication link parameters are used for calculating the link availability.

Research of laser atmospheric propagation of large-aperture antenna measurement

“…1(b), when the sun irradiates the antenna, the thermal convergence effect of the main reflector will cause uneven temperature differences between the main reflector and subreflector. Factors such as atmospheric attenuation and turbulence caused by the instability with the atmosphere and wind will affect the refractive index changes of the laser propagation path, resulting in light intensity scintillation, beam spreading, beam drifting and wavefront aberration [3,4], seriously damaging the stability of laser propagation, and thus affecting the accuracy of the pose measurement of the antenna subreflector.…”

Research on laser spectrum of large-aperture antenna subreflector pose measurement

“…Based on the laser measurement method, almost all the solar energy is concentrated on the subreflector due to the convergence of the antenna itself, which leads to a strong energy of the subreflector, and then the laser signal is easily drowned out [6] . Due to the instability of the near ground atmosphere, the atmospheric attenuation will weaken the laser transmission in different spectral bands, and the harsh environment near-ground caused by atmospheric turbulence will also lead to changes in the light intensity and phase of laser spots, which will reduce the measurement accuracy of laser method [7] .…”