地物特征与其光谱特征的关系是解译遥感影像的关键。本研究利用ASD便携式地物光谱仪对上海崇明国际湿地公园人工湖中的沉水植物狐尾藻的反射光谱进行了初步研究。结果表明,随狐尾藻盖度的增加,其光谱反射率、一阶和二阶导数红边斜率的峰值也相应增加,不同盖度狐尾藻的光谱反射率的差异主要表现在500—650nm和700—900nm波段范围。分别对狐尾藻盖度与这些波段的光谱反射率及根据一阶和二阶导数获得的光谱指数进行回归分析,得到了较好的线性关系。应用回归分析得到的线性方程,可以根据测定的光谱反射率定量反演水体中的狐尾藻盖度。研究结果可为监测大型沉水植物的高光谱遥感影像解译和分类提供技术支撑,为大尺度遥感监测沉水植物的分布和动态变化提供科学依据。

The relationship between land features and their spectral characteristics is mi portant for the interpretation of remote sensing mi ages. In this study, the spectral characteristics of a submerged plant Myriophyllum spicatumwith varied coveragewasmeasuredwith a ground sensor/radiometer, FieldSpecTMPro JR spectroradiometer in the constructed lake of“Chongming InternationalWetland Park”, Shangha.i The results\nshowed that the reflectance rate and the“red edge peak”of the first and second derivation ofMyriophyllum spicatumrose with its increasing coverage, whichwas exhibited both at the visible band(500—650nm) and the near infrared band(700—900nm). A regression analysiswas carried out respectively between the coverage of Vallisneria spiralisand the reflectance rate, spectral indices at the wavelengthswhere the coverage responded the strongest. These resultsofregression analyses showed a clear linear relationship, and bywhich the coverage of Myriophyllum spicatumcould be quantitatively deduced from the reflectance rate measured in situ. The mi plications of this in terms of the ability of hyperspectral remote sensing to distinguish and monitor the distribution and dynamics of submerged vegetation on a large scale are discussed.