Liu Xiaoquan, Wang Xinwei, Zhou Yan, Liu Yuliang
Appl Opt. 2016 Jun 20;55(18):4850-5. doi: 10.1364/AO.55.004850.
For the in situ detection technologies of planktons and fishes, optical cameras traditionally have a small and fixed sampling volume with a strong target-sized dependent (typically<1 mm), and imaging sonar has lower spatial resolution (typically>2 cm) with a problem of species identification. To solve the above problems, this paper proposes an in situ detection method of optical gated sampling for millimeter- to centimeter-scale plankton and fish detection. In this method, the sampling volume can be flexibly adjusted by matching the temporal parameters of gate pulses and illuminator laser pulses to satisfy target observation with different sizes. The gated sampling suppresses the backscattering of water and also filters the environment background so that transparent planktons can be detected by high contrast. Furthermore, the sampling volume is determined by the convolution of gate pulses and laser pulses, and thus the target abundance is derived. Theory and simulation of abundance measurement are established. In experiments, transparent jellyfishes are recorded with a spatial resolution of better than 100 μm. In addition, proof experiments of sampling volume adjustment and abundance measurement are demonstrated.
对于浮游生物和鱼类的原位检测技术，传统光学相机的采样体积小且固定，与目标大小密切相关（通常小于1毫米），成像声纳的空间分辨率较低（通常大于2厘米）且存在物种识别问题。为解决上述问题，本文提出一种用于毫米至厘米尺度浮游生物和鱼类检测的光学选通采样原位检测方法。该方法通过匹配选通脉冲和照明激光脉冲的时间参数，可灵活调整采样体积，以满足不同大小目标的观测需求。选通采样抑制了水体的后向散射，还过滤了环境背景，从而能够以高对比度检测透明浮游生物。此外，采样体积由选通脉冲和激光脉冲的卷积确定，进而得出目标丰度，并建立了丰度测量的理论和模拟。在实验中，以优于100微米的空间分辨率记录了透明水母。此外，还展示了采样体积调整和丰度测量的验证实验。
