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以山东栖霞为研究区,基于TM和ALOS影像获取花期苹果树的冠层反演反射率,结合实测反射率,构建并筛选氮素敏感光谱指数,以敏感光谱指数为自变量,建立氮素反演模型,利用精度最高模型进行空间反演.结果表明:光谱指数与氮素营养相关性为:冠层>叶>花,敏感指数构成以绿、红、近红外波段为主;反演模型精度为:支持向量机回归>逐步回归>单变量回归;基于不同影像的反演结果近似,叶N含量均以3~4等(27~33 g·kg-1)为主,冠N指标均以2~4等(TM:38~47 g·kg-1;ALOS:32~41 g·kg-1)为主;基于不同影像的空间布局亦类似,研究区北部和南部的营养水平高于中部,叶N和冠N高等级区域位于西北部的苏家店镇和松山街道、东北部的臧家庄镇和亭口镇、南部的蛇窝泊镇等,与苹果生产重点镇布局一致.此研究为果树营养状况的宏观数据获取提供了可行方法,也可为其他类似遥感反演提供借鉴.
Taking Qixia of Shandong Province as the research area, the canopy inversion reflectance of flowering apple tree was obtained based on TM and ALOS images. Combined with the measured reflectance, the nitrogen sensitive spectral index was constructed and screened. The sensitive spectral index was used as the independent variable to establish the nitrogen The results showed that the correlation between spectral index and nitrogen nutrition was as follows: canopy> leaf> flower. The sensitive index was mainly composed of green, red and near infrared bands. The precision of inversion model Is: SVM regression> stepwise regression> univariate regression. Based on the inversion results of different images, the content of leaf N is mainly 3-4 (27-33 g · kg-1) 2 ~ 4, etc. (TM: 38-47 g · kg -1; ALOS: 32-41 g · kg -1). The spatial distribution based on different images was also similar. The nutrition level in the northern and southern parts of the study area was higher than that in the middle part , Leaf N and crown N high-level area is located in the northwest Sujiadian and Songshan streets, the northeast of Zangjiazhuang and Tingkou Town, the southern snake nest town, and apple production of key towns layout.The study is fruit tree nutrition The availability of macroscopic data provides a viable approach and provides a reference for other similar remote sensing inversion.