水下激光通信上行传输特性研究

采用谱分析的方法,建立三维随机海浪的模型;根据大气折射率高度模型,对变折射率大气进行分层。在理论上分析激光通过随机起伏的海面和折射率不均匀分布的大气后,到达卫星接收机平面时形成的光斑的形状、位置和大小。仿真结果表明,海面随机起伏对上行光传输的影响取决于发射光束覆盖的海面区域,即海面光斑的尺寸与海浪波长的相对关系。当海面光斑的尺寸相对很大或很小时,对上行光传输的影响可忽略;在其它情况下通过适当调整发射光束的宽度可以提高通信的质量和稳定性。

Study of upward transmission characteristics in submarine laser communication

Adopting sea wave spectra analysis method,three-dimensional random sea wave model is established.According to the height model of air index,the aerosphere with variable index is divided into different layers.Going through radom fluctuant sea surface and air of which refractive index unevenly distributing, laser beam arrives at the satellite receiver plane.Shape,position and size of spot formed at the receiver plane is analysed in theory.Simulation results indicate that the influences of sea's random undulation lie on the relative relation between spot's size formed at the sea surface and the wavelength of sea wave.If the relative size of spot at sea surface is very large or small,the effects to uplink laser transmission are neglectable.At other conditions,the quality and stability of communication can be approved by adjusting the emissive beam properly.