溢油海水双向反射分布函数的建模及仿真*

摘要

溢油海水双向反射分布函数(BRDF)研究可为海水表面油膜及海水中溢油乳浊液检测提供理论基础,对保护海洋周边环境及海洋生态平衡具有重要的意义.本文基于蒙特卡罗方法及Mie散射理论建立了溢油海水模型,针对532 nm及355 nm激光研究了无溢油海水、漂浮油膜海水及乳浊液海水情况下海水的BRDF,并给出不同油膜厚度及溢油浓度下海水的BRDF.结果表明双向反射分布函数对水体的污染程度十分敏感,相同观测角下,溢油海水BRDF值明显小于无溢油海水BRDF值,海水的BRDF值随油膜厚度及溢油浓度的增加而减小.海水的BRDF值可作为海水是否发生溢油污染及污染程度判断依据之一.%Study on the bidirectional reflectance distribution function (BRDF) of seawater with spilt oil will provide a the-oretical basis for detection of oil film on sea surface and oil emulsion in sea water, which will be of great significance for protection of marine environment and marine ecological balance. In this paper a model of BRDF for oil-polluted seawater has been developed by applying Monte Carlo method and Mie scattering theory. The BRDFs of clean seawa-ter, oil-covered seawater, and oil-emulsion seawater are investigated at wavelengths of 532 nm and 355 nm. Simulation results of different film thicknesses and oil emulsion concentrations are presented. Results show that the BRDF is rather sensitive to the degree of pollution in seawater. The presence of oil film or oil emulsion will cause a decrease of the BRDF. At the same angles of observation, the BRDF value of seawater decreases with the increase of oil film thickness and oil emulsion concentration. Oil spill detecting and monitoring can potentially be achieved using BRDF data from optical sensors.