不同天气条件下蓝绿激光下行跨介质传输特性  

Characteristics of Blue-green Laser Downlink Cross-media Transmission under Different Weather Conditions

作　　者：李聪[1] 袁瑞蔓 高洪 张亭禄[2] 孙博[1] 陈特 曹桂兴[1] LI Cong;YUAN Ruiman;GAO Hong;ZHANG Tinglu;SUN Bo;CHEN Te;CAO Guixing(Institute of Telecommunication and Navigation Satellites,China Academy of Space Technology,Beijing 100094,China;Department of Marine Technology,Ocean University of China,Qingdao,Shandong 266100,China)

机构地区：[1]中国空间技术研究院通信与导航卫星总体部,北京100094 [2]中国海洋大学海洋技术系,山东青岛266100

出　　处：《光子学报》2021年第12期34-48,共15页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.61675232,61975234)。

摘　　要：采用蒙特卡洛仿真方法,分析了三种典型天气条件(晴天、层云和卷云)下激光在大气-海气界面-水体中的下行传输特性。结果表明:不同天气条件下经过大气传输到达海面的激光角分布明显不同,晴天时角分布发散很小,层云条件下发散严重,卷云条件下发散明显;晴天与层云条件下到达海面的光斑尺寸接近,而卷云条件下光斑大15%左右。不同天气条件下,激光经过大气、海气界面后角分布表现出不同的特征,晴天时海面使激光角分布发散变大,且随风速的增加发散呈变大的趋势;层云条件下海面使角分布发散变小,且随风速的增加发散呈变小的趋势;卷云条件下激光角分布变化复杂。不同天气条件下,激光经过大气、海气界面、水体后,既有相同特征又有不同之处。当水较浅时,三种天气条件下角分布表现出不同特征,水较深时角分布趋于一致;晴天和层云条件下的光斑尺寸基本不随水深变化,卷云条件下随深度增加明显减小。不同天气条件下光斑中心能量随深度的变化存在一定差异,晴天时平均变化率约为−0.410 dB/m,层云和卷云条件下分别为−0.426 dB/m和−0.413 dB/m。研究结果可为蓝绿激光跨介质通信链路预算、系统设计及参数优化提供参考。The characteristics of laser downlink cross-media transmission through atmosphere,rough sea surface and seawater under three typical weather conditions(clear day,stratus and cirrus)are analyzed by using Monte Carlo simulation method.The results show that,the angular distributions of the light propagating through atmosphere are different under different weather conditions.The divergence is small under clear day condition,which is serious under stratus condition and obvious under cirrus condition.The difference between the spot sizes under clear day and stratus conditions is small,while the size under cirrus condition is about 15%larger.The laser shows different characteristics propagating through atmosphere and sea surface under different weather conditions.The angular divergence is larger and increases with wind speed under clear day condition.It is smaller and decreases with wind speed under stratus condition.The angular divergence changes complicatedly under cirrus condition.Under different weather conditions,there are similar characteristics of light propagating through atmosphere-surface-sea as well as differences.The characteristics of the angular distributions are different in shallow water,while similar in deep water.The spot size changes little with water depth under clear day and stratus conditions,while it decreases as the depth increases under cirrus condition.In addition,the spot center energy attenuation with depth is different under different weather conditions.Under clear day condition the average rate of change is about−0.410 dB/m,while under stratus and cirrus conditions about−0.426 dB/m and−0.413 dB/m respectively.The results could offer a reference for blue-green laser cross-media communication link budget,system design and parameter optimization.

关 键 词：水下通信 信道传输特性 蒙特卡洛 天气影响 激光 

分 类 号：P733.3[天文地球—物理海洋学] N32[天文地球—海洋科学]