Near-surface atmospheric turbulence profile measuring technology based on an airship-mounted laser communication system.

Abstract

Atmospheric turbulence is an important factor affecting the transmission performance of free-space optical communications (FSOC), especially in the near-surface where the atmospheric turbulence characteristics are complex and variable. In this paper, we study the real-time measurement technique of a near-surface atmospheric turbulence profile of an airship-borne laser communication system based on the principle of light intensity scintillation. Aiming at the influence of an avalanche photon diode detector system noise and environmental factors such as background light and platform vibration on the measurement results, a noise-canceling scintillation index calculation method, combined with a wavelet threshold denoising method, is proposed to improve the accuracy of atmospheric turbulence profile measurements. We build a communication distance of 12 km airship-borne laser communication experiment and carry out a real-time measurement of turbulence profile under 1 km near the ground without affecting the laser communication rate of 2.5 Gbps data transmission. The experimental results show that the atmospheric turbulence profile measured in real time follows the same trend as the theoretical simulation curve of the Hufnagel-Valley model, and the jitter of the measured values after denoising is significantly smaller than that of the measured values without denoising. The research results provide technical guidance and data support to promote the development of space laser communication and adaptive optics.