水中颗粒物大角度范围体散射函数测量方法

Wide angle volume scattering function measurement methods for particles in water

针对现有体散射测量系统中激光器与探测器相互遮挡导致探测角度减小的问题,设计了一款新型的水中颗粒物的体散射函数测量系统。首先,通过双潜望式光路结构,将激光发生平面与散射探测平面分离,减小了激光器对探测角度的遮挡;同时,通过潜望式出射棱镜将透射光导出水体,避免了容器的杯壁散射,提高背散射测量的准确性。根据实际工艺,改进出射棱镜,设计系统样机,实现了3°~178°大角度范围体散射函数的测量。结合系统结构与水下光传输原理,根据数据矫正算法,矫正由于测量光程及水体衰减造成的偏差。对比矫正后结果与米散射仿真结果,证明方法的可靠性。

A system for measuring the volume scattering function of water with particles was built,helping the laser and the detector to avoid the shading of each other that causes the reduce of detection angle. A set of double-periscopic optical system was used to separate the detection plane of scattering plane from laser exiting plane, thus the shelter of the laser source was minimized. What ′ s more, as the transmission light was exported from the system, the scattering light of water container was avoided so that the precision of backscatter measurement was promoted. The prism for exporting underwater light was designed according to the manufacturing techniques and by which the scattering measurement equipment was designed to measure the scattering light ranges from 3° to 178°. Next, according to the structure of the system and the principle of optical transmission in water, data rectifying methods was designed to rectify the deviation of measurement optical distances and light absorption. The rectified results were finally compared with simulated results of Mie scattering, the main source of deviation was analyzed and the improvement scheme of the system was proposed.