Walcarius Kevin, Rosin Joachim, Hespel Laurent, Chami Malik, Dartigalongue Thibault
Opt Express. 2023 Jul 31;31(16):26194-26207. doi: 10.1364/OE.491860.
3D laser imaging technology could allow visualizing objects hidden in turbid water. Such a technology mainly works at short distances (<50 m) because of the high attenuation of light in water. Therefore, a significant part of the scattering events from the water column is located out of the optical depth of field (DoF), which could induce optical blur on images. In this study, a model is proposed to represent such an optical blur, based on geometric optics. The model is then implemented in a Monte-Carlo scheme. Blur significantly affects the scattered signal from water before the DoF in monostatic conditions, but has less impact in bi-static conditions. Furthermore, it is shown that blur enables a very large variance reduction of 2D images of objects situated within the DoF. Such an effect increases with the extinction coefficient.
三维激光成像技术能够使隐藏在浑水中的物体可视化。由于光在水中的高衰减，这种技术主要在短距离（<50米）内起作用。因此，水柱散射事件的很大一部分位于光学景深（DoF）之外，这可能会在图像上产生光学模糊。在本研究中，提出了一个基于几何光学的模型来表示这种光学模糊。然后在蒙特卡罗方案中实现该模型。在单基地条件下，模糊对景深之前来自水的散射信号有显著影响，但在双基地条件下影响较小。此外，结果表明，模糊能够极大地降低景深内物体二维图像的方差。这种效果随着消光系数的增加而增强。
