You Yu, Tonizzo Alberto, Gilerson Alexander A, Cummings Molly E, Brady Parrish, Sullivan James M, Twardowski Michael S, Dierssen Heidi M, Ahmed Samir A, Kattawar George W
Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843-4242, USA.
Appl Opt. 2011 Aug 20;50(24):4873-93. doi: 10.1364/AO.50.004873.
Polarization states of the underwater light field were measured by a hyperspectral and multiangular polarimeter and a video polarimeter under various atmospheric, surface, and water conditions, as well as solar and viewing geometries, in clear oceanic waters near Port Aransas, Texas. Some of the first comprehensive comparisons were made between the measured polarized light, including the degree and angle of linear polarization and linear Stokes parameters (Q and U), and those from Monte Carlo simulations that used concurrently measured water inherent optical properties and particle volume scattering functions as input. For selected wavelengths in the visible spectrum, measured and model-simulated polarization characteristics were found to be consistent in most cases. Measured degree and angle of linear polarization are found to be largely determined by an in-water single-scattering model. Model simulations suggest that the degree of linear polarization (DoLP) at horizontal viewing directions is highly dependent on the viewing azimuth angle for a low solar elevation. This implies that animals can use the DoLP signal for orientation.
在得克萨斯州阿兰萨斯港附近清澈的海水中，利用高光谱多角度偏振计和视频偏振计，在各种大气、海面和水体条件以及太阳和观测几何条件下，测量了水下光场的偏振态。对测量得到的偏振光（包括线偏振度和角度以及线性斯托克斯参数Q和U）与蒙特卡罗模拟结果进行了一些首次全面比较，蒙特卡罗模拟使用同时测量的水体固有光学特性和粒子体积散射函数作为输入。对于可见光谱中的选定波长，在大多数情况下，测量得到的偏振特性与模型模拟结果一致。发现测量得到的线偏振度和角度在很大程度上由水中单散射模型决定。模型模拟表明，对于低太阳高度，水平观测方向的线偏振度（DoLP）高度依赖于观测方位角。这意味着动物可以利用DoLP信号进行定向。
