摘要
根据推广的Huygens-Fresnel原理推导了不同接收机高度斜程传输情况下波束的扩展半径。同时结合Mellin变换,导出了考虑外尺度情况下准直激光波束漂移方差模型,可以退化到不考虑外尺度时漂移方差。数值计算中应用ITU-R公布的随高度变化的大气结构常数模型,结果表明,斜程大气湍流中波束的漂移方差、扩展半径依赖于接收机高度和初始波束半宽。随仰角的增加,波束的有效半径和漂移方差不断减小;累积效应斜程传输波束受大气湍流的影响比水平传输要小得多。
According to Huygens-Fresnel principle, the spreading radius are obtained with different heights of drone on the slant path. At the meantime, the Mellin transform technique is applied to the wander effects of the collimating laser beam propagation in atmospheric turbulence on the slant path and can degenerate to the result of the zone outer-scale. Applying the ITU-R turbulence structure constant model, the beam spreading and wander variance are analyzed. Influence of the height of drone and initial beam radial on beam spreading and wander on the slant path are discussed. With the increase of the elevation, the beam effective radius and wander variance become smaller and smaller. The integral effect of the atmospheric turbulence to laser beam propagation on the slant paths is smaller than that on the horizontal paths, it is because the intensity of the turbulence is weaker as of the height of receiver increases.
出处
《电波科学学报》
EI
CSCD
北大核心
2008年第4期611-615,共5页
Chinese Journal of Radio Science
基金
国家自然科学基金(60371020)
关键词
大气湍流
斜程传输
波束扩展
波束漂移
atmospheric turbulence
slant path
beam spreading
beam wander
