光源偏振对水体颗粒后向散射系数测量的影响

发布时间：2018-03-10 02:01

本文选题：偏振　切入点：后向散射系数　出处：《光谱学与光谱分析》2016年01期 　论文类型：期刊论文

【摘要】：颗粒后向散射系数是水体主要的固有光学特性,也是海洋水色的决定因子和海洋水色卫星遥感反演的基础参数。当前,利用光学仪器现场原位测量是获取水体颗粒后向散射系数的主要方法。由于光源自身和仪器光路中镜面反射和折射,其出射光源可能存在一定的偏振,进而会影响水体后向散射系数测量的精度。目前,关于水体后向散射系数测量仪器的光源偏振性及其对颗粒后散射系数测量精度影响的研究尚为空白。针对该问题,以应用广泛的水体后向散射测量仪HydroScat6(HS-6)为例,对其出射光源的偏振特性进行了系统测量,并进一步开展了光源偏振对水体颗粒后向散射系数测量精度影响的实验研究。结果表明,HS-6六个光学通道除590nm通道出射光源偏振度略低外(~15%),其他通道出射光源中心波长偏振度均在20%~30%。因此,HS-6出射光源具有显著的偏振特性。光源偏振对颗粒后向散射系数测量具有不可忽略的影响,且影响程度随着波段,线偏振角度及悬浮泥沙浓度而变化。不同悬浮泥沙浓度下,光源偏振引起的420,442,470,510,590和670nm六个波段的平均偏差可达15.49%,11.27%,12.79%,14.43%,13.76%,12.46%。因此,利用光学仪器现场测量颗粒后向散射系数需要考虑光源偏振的影响,并需尽可能降低出射光源的偏振度。
[Abstract]:The backscattering coefficient of particles is the main inherent optical property of water body, and also the determining factor of ocean water color and the basic parameter of remote sensing inversion of ocean water color satellite. In situ measurement with optical instruments is the main method to obtain backscattering coefficient of water particles. Due to the reflection and refraction of the mirror surface in the light source itself and in the instrument path, the light source may have some polarization. At present, the research on the polarization of light source and its influence on the measurement accuracy of backscattering coefficient of water body is still blank. Taking HydroScat6 HS-6, a widely used backscatter measuring instrument, as an example, the polarization characteristics of its outgoing light source are systematically measured. The experimental study on the effect of light source polarization on the measurement accuracy of backscattering coefficient of water body particles is carried out. The results show that the six optical channels of HS-6 except 590nm channel have a slightly lower degree of polarization of the outgoing light source, and other channels have the center of the outgoing light source. The polarization of the light source of HS-6 has remarkable polarization characteristics. The polarization of the light source has an important influence on the measurement of the backscattering coefficient of particles. And the influence degree varies with the band, linear polarization angle and suspended sediment concentration. Under different suspended sediment concentration, the average deviation caused by light source polarization in the six bands of 420,442,470,510,590 and 670 nm can reach 15.49. In order to measure the backscattering coefficient of particles in situ by optical instruments, the influence of polarization of light source should be considered, and the degree of polarization of light source should be reduced as much as possible.
【作者单位】：卫星海洋环境动力学国家重点实验室国家海洋局第二海洋研究所;遥感与智能信息系统研究中心中国科学院西安光学精密机械研究所;
【基金】：国家科技支撑计划项目(2013BAD13B01) 国家(863计划)课题(2014AA123301) 国家自然科学基金项目(41322039,41271378,41321004) 全球变化与海气相互作用专项项目(GASI-03-03-01-01)资助
【分类号】：P715.7;O436.3

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