光检测尾流特征中抑制背景干扰的方法

Restraint Method of Background Interference for Detection of Light Wakes

依据鱼雷光检测尾流的背景干扰的主要来源及其特征,给出了有效抑制背景干扰的方法。理论和实验研究表明,采用以下方法,可有效抑制背景干扰:给光电探测系统加装窄带光谱滤波器,其透光的谱线宽度应恰好覆盖照明激光的辐射频谱,由于照明激光的谱线很窄,可有效抑制环境背景光的干扰;对于气泡的前向散射和后向散射,采用前向散射测量能较好地抑制水分子、水中固体悬浮颗粒的散射干扰;在测量气泡散射的各种物理量中,测量气泡的散射光空间频谱分布,通过高斯拟合,以散射光空间频谱分布的线宽表征气泡的空间分布,是一种有效的光检测尾流方法,并且可以进一步抑制与激光光谱重叠部分环境背景光的干扰。研究结果为光检测尾流的实际应用奠定了理论和实验基础。

A restraint method of background interference for detection of light wakes is presented according to the source and characteristics of background interference. The theoretical and experimental investigations show that the valid ways to restrain the background interference are as follows： to set up a narrowband optical spectrum filter on a photoelectric detector with its narrowband spectrum width just covering the radiation spectrum of illuminating laser; to apply the forward scattering measurement to effectually restrain the scattering interference of water molecules and suspended solid particles; and to measure the scattered light＇ s spatial spectrum intensity distribution of air bubbles in water in order to characterize the air bubbles＇spatial distribution by the full width at half maximum （FWHM） of the measured light distribution via Gaussian fitting and thus to detect ship wake, which can moreover restrain the interference of sunlight whose spectrum is coincidence with that of laser radiation. The result could be applied to detection of light wakes.