多角度测量石油类污染水体后向散射系数的方法研究

Study on the Backscattering Coefficient of Petroleum Polluted Waters with Multi-Angle Measurement

后向散射系数bb是水体固有光学参数之一,在水色遥感模型建立中起着重要的作用。目前主要利用美国Hobilabs公司的Hydro Scat-6(HS-6)或美国Wetlabs公司的BB-9两种后向散射测量仪器在现场进行测量。石油类污染水体中石油类物质与悬浮泥沙共同影响着水体后向散射系数bb,这两种仪器的测量值都是基于单一角度而获取的,难以实现利用其来进一步区分石油类和悬浮物的后向散射系数贡献。通过对纯水、石英砂微粒、油污水进行各种配比试验,获取不同组合样本,利用美国Sequoia Scientific公司的LISST-100X粒径仪和美国Wyatt公司的Dawn Heleos II(DAWN)十八角度静动态激光散射仪,结合Mie散射算法,探索出两种多角度获取bb的方法。一种是利用LISST-100X粒径仪测量值,再基于Mie散射算法计算得到;另一种方法是对Dawn Heleos II十八角度静动态激光散射仪进行定标以后,利用其测量值计算出bb。对比分析了两种方法所获取的结果,并对产生误差的原因进行了分析。

As one of the inherent optical parameters of waters, the backscattering coefficient bbplays a significant role in water remote sensing modeling. Actually, there are oil particles adhering to suspended sediments in waters. Currently, the Hydro Scat-6（HS-6） and BB9, instruments respectively developed by the Hobilabs and Wetlabs, are mostly used for bbin-situ measurement. The bbcan be influenced by petroleum substances and suspended sediments jointly in petroleum polluted waters. In addition, the data are obtained based on a single angle, which gives rise to great difficulty in further distinguishing the contributions of petroleum and suspended sediments to backscattering coefficient. Different combination samples are obtained through mixing various amounts of pure water, quartz sand and petroleum polluted water. The LISST-100X（Laser In-situ Scattering and Transmissometry） developed by Sequoia Scientific, as well as Dawn Heleos II（Multi-Angle Static Light Scattering Detector） developed by Wyatt, are adopted combined with the Mie scatter algorithm, so as to figure out bb; and the other approach is to use Dawn Heleos II to derive bbafter calibration and measurement. This paper compares and analyzes the results of the two methods, and probes into the cause of errors.