锚泊光学浮标浮体设计及近海试验
收稿日期: 2009-05-06
修回日期: 2009-11-08
网络出版日期: 2010-03-23
基金资助
国家863计划重大项目(2006AA09A310); 中国科学院重要方向性项目及装备项目(KZCW2-YW-215)
Design and test of moored optical buoy
Received date: 2009-05-06
Revised date: 2009-11-08
Online published: 2010-03-23
文中设计的光学浮标采用了柱状浮体, 提出了自由旋转的马鞍链结构。理论计算结果表明, 该光学浮标一是初稳性高度大, 二是光学浮标重心位于浮心之下, 浮标的摇摆角较小, 抗倾斜及倾覆能力强。海上试验结果表 明, 对于风力7节、浪高3—4m以下的海况, 浮标倾角≤5°的次数占总采样次数的 54%, 浮标倾角≤10°的次数占总采样次数的83%, 浮标性能较好地满足了水下光辐射测量的技术要求。为减小阴影效应带来的光辐射测量误差, 文中采用了两种解决方法: 一是伸臂结构解决浮标体阴影的影响, 当太阳天顶角为0°时, 在近岸或者清洁水体中浮标体阴影引起的向上辐亮度测量误差分别不大于4% 和1%; 二是光纤光谱仪测量技术减少仪器自阴影的影响, 设计的光谱辐照度和辐亮度光学探头直径均为0.042m, 当水体光束衰减系数为0.12m-1, 太阳天顶角为10°时, 自阴影引起的向上辐亮度测量误差仅为1.5%。
曹文熙 , 杨跃忠 , 张敬祥 , 柯天存 , 卢桂新 , 李彩 , 郭超英 , 孙兆华 . 锚泊光学浮标浮体设计及近海试验[J]. 热带海洋学报, 2010 , 29(2) : 1 -6 . DOI: 10.11978/j.issn.1009-5470.2010.02.001
A spar body was considered and a free-rotated saddle was used in a moored optical buoy. Theoretical results indicated that the buoy’s high initial stability enables it to be stable. Due to the centre of gravity position being lower than the buoyant centre, the rolling angle of the buoy is small, as it would result in strong ability to resist tilting and capsizing. In situ experiment results indicated that 83% of the buoy’s tilt angles are ≤10° and 54% of the buoy’s tilt angles are ≤5° under the conditions of wind speed less than 7 knots and wave height less than 3-4m, therefore the buoy performance satisfies the technical requirement for underwater light measurements. To minimize the shelf–shading effects on the light measurements, two solutions were found: First of all, stroked-out structures were used to avoid shelf-shading of buoy body, and when the solar zenith angle was 0°, the shelf-shading errors of upwelling radiance were lower than 4% and 1% for coastal and open oceans, respectively; Second, fiber spectrometer was used to avoid shelf-shading of sensors. The diameter of designed optical sensors for irradiance and radiance was 0.042m. When the beam attenuation coefficient was 0.12m-1 and the solar zenith angle was 10°, the self-shading error was 1.5% for upwelling radiance.
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