基于PLS-SVM耦合算法的射阳河口无机氮磷营养盐浓度监测研究  

Concentration of dissolved inorganic nitrogen and dissolved inorganic phosphorus by Hyperion near Sheyang Estuary

作　　者：许勇[1,2] 成长春[2] 张鹰[3] 张东[3] 

机构地区：[1]盐城师范学院城市与资源环境学院,江苏盐城224002 [2]盐城师范学院江苏沿海开发研究院,江苏盐城224002 [3]南京师范大学地理科学学院,江苏南京210046

出　　处：《海洋环境科学》2013年第3期398-403,共6页Marine Environmental Science

基　　金：国家自然科学基金:我国沿海经济低谷区港口;城镇;产业联动发展模式研究(以江苏沿海为例)(41071083);江苏省高校自然科学研究面上项目:江苏近海表层无机氮磷营养盐浓度遥感监测研究(11KJB170010);盐城师范学院教授;博士基金:江苏近海表层无机氮磷营养盐浓度遥感监测研究(10YSYJB0207)

摘　　要：利用射阳河口实测光谱模拟Hyperion各波段反射率并与DIN、DIP浓度作相关性分析,发现DIN、DIP浓度都表现为与近红外波段的反射率呈较强的正相关,而与蓝波段的反射率呈较弱的负相关,这种相关性特征和该海域水体浊度与光谱反射率间的相关性基本一致,这说明就某一时间段而言,该海域的DIN和DIP主要来源于沉积物再悬浮过程中的释放。引入了偏最小二乘和支持向量机回归耦合(PLS-SVM)的算法,通过偏最小二乘在Hyperion的波段中提取出对DIN和DIP浓度有较强解释作用的8～16波段和37～57波段,从这些波段中提取出两个成分并利用支持向量回归建立反演模型,采用ε-不敏感损失函数,通过比较,确定DIN浓度反演模型的参数组合是C=10、γ=0.05、ε=0.1;DIP浓度反演模型的参数组合是C=1、γ=0.1、ε=0.001,模型预测的平均相对精度达到75%左右,影像反演的结果与实际情况相当吻合。The correlations are calculated between the spectrum of Hyperion simulated from the in-situ spectrum and the synchronous concentration of DIN and DIP collected in Sheyang Estuary.The results show that DIN and DIP concentration have positive correlation coefficients in near-infrared regions and negative correlations in blue regions.The correlations between the turbidity and spectrum have the same characters.All the results indicate that DIN and DIP in this sea area are mainly originated from the sediment resuspension in normal status.The regression algorithm coupled with partial least square and support vector machine（PLS-SVM） is used to establish the retrieving model of Hyperion image.The band 6~16 and 37~57 of Hyperion are selected by the method of PLS regression for their strong explaining capability to DIN and DIP concentration,two principle components are extracted from these bands to construct the model.The support vector machine regression models are established by using ε-insensitive loss function.The parameters of DIN and DIP retrieving model are C=10、γ=0.05、ε=0.1 and C=1、γ=0.1、ε=0.001 after comparing all the parameter combinations,the relative accuracy of the models arrives about 75%.The distribution of DIN and DIP retrieved by the models is consistent well with the real conditions.

关 键 词：HYPERION DIN DIP 射阳河口 PLS-SVM 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]