现代飞机装备机载光电探测系统，采用红外热像仪搜索空域飞机目标的方位，利用脉冲激光测距机测量目标的径向距离。机载脉冲激光目标检测是一个动态过程，当光斑在目标上移动或大气湍流折射导致回波光束偏离接收天线时，目标时有时无，导致无法稳定跟踪目标。仅利用目标回波脉冲的幅度信息进行检测，限制了激光目标的有效作用距离。在机载平台的动态杂波背景下，将脉冲激光目标视为距离扩展目标，回波信号看作目标波形像，结合时间宽度上的波形特征开展检测，可较好解决动态目标检测问题。鉴于此，文中提出了一种基于小波变换的多脉冲激光距离扩展目标回波滤波算法。实验结果表明，所提算法能够较好地保持波形特征。

In this Letter, a single scattering turbulence model in a narrow beam case for ultraviolet (UV) communication is proposed based on the division of the effective scattering volume. This model takes the variation of atmospheric scattering, absorption, and turbulence in different paths into account. Meanwhile, the applicable transceiver configurations of this model are provided by analyzing path loss error caused by the single scattering assumption in the UV channel. Furthermore, we investigate the effect of turbulence on the probability density function of the arriving power in both coplanar and non-coplanar scenarios. The averaging effect of multipath propagation on the arriving power’s fluctuations is presented. Then, the bit-error-rate performance is also studied. This work provides an efficient way for UV turbulence channel estimation.

A sunlight communication system is proposed that uses Sr₂Si₅N₈:Eu²⁺ phosphors to concentrate sunlight signals in strong background light noise; thus, a wide spectrum sunlight communication system is converted into a narrow spectrum one. A communication method is proposed to enable compression to the dark line H-α (656.28 nm) spectrum. A 50% solar energy conversion efficiency is achieved with a 0.3 μs code delay, a 0.2 μs code rise time (20%–80%), and a 96% optical transmittance. Experimental results show that phosphors enhance the sunlight intensity 1.5 times with the same distance. This method has immense potential in future long-distance sunlight communication.