船运铁矿粉污染海冰反射光谱特征研究  

Study on Reflection Characteristics of Sea Ice Contaminated by Shipping Iron Ore Powder

作　　者：刘丙新[1] 郭刚 吴东来 刘成玉[2] 谢锋[2] LIU Bing-xin;GUO Gang;WU Dong-lai;LIU Cheng-yu;XIE Feng(Navigation College,Dalian Maritime University,Dalian116026,China;Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai200083,China)

机构地区：[1]大连海事大学航海学院,辽宁大连116026 [2]中国科学院上海技术物理研究所,上海200083

出　　处：《光谱学与光谱分析》2021年第2期489-493,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(51509030);辽宁省自然科学基金项目(20180550362);大连市科技创新基金项目(2017RQ065)资助。

摘　　要：国际防止船舶造成污染公约(MARPOL)中关于防止船舶垃圾污染的附则V规定,对含有海洋环境有害的物质(HME)的干燥残留物必须在适当的港口接收设施中排放,但因费用等因素影响,很多船只将废弃物直接抛弃于海洋中。散落于海冰表面的船运铁矿粉会污染海冰品质,并加速海冰融化,对海洋环境造成一定的污染。对铁矿粉污染海冰的光谱反射率特征的研究,能够为利用光学遥感影像进行海冰品质监测提供数据基础。通过现场测量覆盖不同面积比例铁矿粉颗粒的海冰和清洁海冰之间光谱特征差异,为港口附近铁矿粉污染的范围以及沉降量的估算提供参考和依据。该研究是在渤海海域天然海冰条件下进行的,获取并分析了不同污染程度的海冰光谱特征,探讨这些光谱特征与铁矿粉颗粒几何截面积比例的相关性。为了反演海冰表面铁矿粉面积比例,利用光谱矢量角余弦值和光谱吸收指数阈值法进行了海冰、铁矿粉端元提取,根据混合像元线性解混模型理论,建立基于特征光谱波段反射率值的海冰表面铁矿粉面积比例反演模型。所研究海冰表面铁矿粉面积比例分为0(洁净海冰),25.8%,37.2%,46.1%,52.1%,65.1%,72.5%,82.3%,92.3%,93.1%和100%(纯铁矿粉)等,数据采集波长范围350~2500 nm。结果表明,利用1460 nm波段处的吸收指数(SAI)进行海冰和铁矿粉端元提取效果最佳,反射率与铁矿粉面积在918~1400,1500~1780和2250~2300 nm波段,相关系数都大于0.90,86%以上波段范围的反射率与铁矿粉面积的相关系数在0.90以上,91.75%以上的波段范围相关系数在0.80以上。选取1610~1630 nm波段的平均反射率估算铁矿粉面积比例,几何截面积较小的误差一般大于几何截面积较大的,在克服海冰背景反射率的影响下,比较精确地估算了海冰-铁矿粉像元中铁矿粉颗粒的几何截面积比例,平均反演精度达到94.23%。Annex V of the Convention on the Prevention of Pollution from Ship(MARPOL)stipulates that dry residues containing substances harmful to the marine environment(HME)must be discharged at port reception facilities.However,many ships discard the waste directly into the ocean.Shipment of iron ore powder scattered on the surface of sea ice will pollute the sea ice and accelerate the melting of it,causing pollution to the marine environment.The research on the spectral reflectance of sea ice contaminated by iron ore powder can provide data basis for sea ice quality monitoring using optical remote sensing images.The purpose of this paper is to provide a reference and basis for the estimation of the range of iron powder pollution by measuring on-site spectral differences between sea ice and that covered iron ore powder particles with different area proportions.The experiment was conducted on natural sea ice in the Bohai Sea.The spectral characteristics of sea ice with iron ore powder were obtained and analyzed,and the correlation between these spectral characteristics and the area fraction of iron ore powder particles was discussed.In order to retrieve the fraction of the area of iron ore powder on the surface of sea ice,the end-member extraction of sea ice and iron ore powder was performed using the spectral vector angle cosine value(Acos)and the spectral absorption index(SAI)threshold.Based on the linear spectral unmixing theory,a feature-based inversion model of iron powder fraction on the surface of sea ice was proposed.The proportion of iron ore powder on the surface of sea ice in this paper is 0(clean sea ice),25.8%,37.2%,46.1%,52.1%,65.1%,72.5%,82.3%,92.3%,93.1%,and 100%(Pure iron ore powder),etc.,the data collection wavelength range is 350~2500 nm.The results show that the absorption index at 1460 nm band is the best for extraction of sea ice and iron ore powder.The reflectance in the range of 918~1400,1500~1780 and 2250~2300 nm have a great correlation with the area fraction,which are all greater than 0.90.The co

关 键 词：海冰 铁矿粉 光谱 

分 类 号：TP722.4[自动化与计算机技术—检测技术与自动化装置]