基于高光谱数据的戈壁地表砾石粒径反演研究

发布时间：2018-07-14 22:29

【摘要】：戈壁地表砾石粒径组成特征反映戈壁形成过程信息,且在很大程度上决定戈壁改造利用的难易,是开展戈壁研究的基础和前提。结合高光谱数据的微分变换,遴选出砾石粒径的敏感波段与反演方程,进行戈壁地表砾石粒径反演研究。结果表明:微分变换后的砾石光谱反射率与粒径有较好相关性,相关性最好的波段为908 nm、983 nm和985 nm。其中,对数倒数微分变换之后的反射率与粒径成正相关(R~2=0.61),而一阶微分、平方根微分、对数微分3种变换形式之后的反射率与粒径呈负相关,相关系数分别为-0.633、-0.646、-0.649。将一阶微分变换后的光谱数据与粒径进行回归分析,发现一元三次回归模型具有较好的拟合精度,其中对数微分在回归分析中表现最好(R2=0.851),经过验证得出对数微分预测精度(75.27%)高于其他4种微分形式的精度,表明砾石光谱的对数微分变换之后的908 nm波段可应用于戈壁地表砾石粒径的反演。
[Abstract]:The characteristics of gravel-size composition of Gobi surface reflect the information of Gobi formation process, and to a large extent determine the difficulty and ease of Gobi reconstruction and utilization, which is the foundation and premise of Gobi research. Based on the differential transformation of hyperspectral data, the sensitive band and inversion equation of gravel particle size are selected, and the inversion of gravel particle size on Gobi surface is carried out. The results show that there is a good correlation between the spectral reflectance and the particle size of the gravel after differential transformation. The best correlation bands are 908 nm ~ 983 nm and 985 nm ~ (-1). Among them, the reflectivity after logarithmic reciprocal differential transformation is positively correlated with particle size (R _ (2) O _ (0.61), but the reflectivity of the first order differential, square root differential and logarithmic differential is negatively correlated with the particle size, and the correlation coefficients are -0.633n- 0.646ng-0.649, respectively. By regression analysis of spectral data and particle size after first order differential transformation, it is found that the cubic regression model has good fitting accuracy. The logarithmic differential is the best in regression analysis (R2C0.851), and the accuracy of logarithmic differential prediction (75.27%) is higher than that of the other four differential forms. It is shown that the 908 nm band after logarithmic differential transformation of the gravel spectrum can be used for the inversion of the gravelly particle size on the Gobi surface.
【作者单位】：枣庄学院旅游与资源环境学院;中国林业科学研究院荒漠化研究所;
【基金】：公益性行业科研专项(201404304) 国家自然科学基金项目(31370708)资助
【分类号】：P941.73;P237

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