大连港外海域船舶尾迹光学特征研究

Study on Apparent Optical Properties of Ship Wakes in the Offshore Sea Near Dalian Harbor

通过大连港外海上实验测量船舶含气泡尾迹表观光学特征(如离水辐亮度、遥感反射率),分析了尾迹气泡对极度混浊的Ⅱ类水体海水表观光学特征的影响。实验结果证明:无论在可见光还是近红外波段,尾迹气泡都增强了海水表观光学量,如"耘海"船尾迹遥感反射率在可见光波段相对背景海水提高了50%,在近红外波段相对提高了159%。数据分析结果表明在此种水体中,气泡使得尾迹海水水色变黄,而不是在Ⅰ类水体中使水色变绿。随着观测点在尾迹中的位置靠近目标船,气泡数密度不断增加,遥感反射率也随之增强。

Based on the apparent optical properties （such as the outward radiance and remote sensing reflec- tance） observed in the shipboard experiments for the ship-wakes with bubbles in the offshore sea near Dalian Harbor, the bubble effects on the apparent optical properties on the Case Ⅱ waters （i.e. very tur- bid water）is analyzed. It is shown from the results of the experiments that wake bubbles enhance the quan- tity of the seawater apparent optical properties of the visible and infrared wave bands. For example, The remote sensing reflectance from the wakes of the ＂Yun Hai＂ ship is 50% higher than the background sea- water in the visible wave band, and 159% higher in the infrared wave bands. As the result of data analysis shows, the ship wakes in this type of water can make the water colour appear in the yellow colour, rather than in the green colour for the Case I water. As the observed location in the shipwakes become closer to the ship stern, both the bubble density and the remote sensing reflectance become greater.