%0 Journal Article
%T The Vertical Distribution Characteristic and Spectral Response of Canopy Nitrogen in Different Layer of Winter Wheat<br>冬小麦冠层氮素的垂直分布及光谱响应
%A WANG Ji-hu
%A WANG Zhi-jie
%A HUANG Wen-jiang
%A MA Zhi-hong
%A LIU Liang-yun
%A ZHAO Chun-jiang
%A <br>王纪华
%A 王之杰
%A 黄文江
%A 马智宏
%A 刘良云
%A 赵春江
%J 遥感学报
%D 2004
%I 
%X The precision of quantificational remote sensing can be enhanced by tapping the potential of sensor,transfer model and exact describing of the object. We think exactly of describing the object is the base of enhancing inversion precision of remote sensing. For this purpose,the vertical distribution of canopy nitrogen and Chl (a b) status in winter wheat were studied. The spectral response of nitrogen and Chl(a b) at different layer in canopy also had been analyzed. There appeared an apparent descending trend of nitrogen content from the upper layer to the lower layer. The nitrogen content of upper layer was higher than that of the middle layer with 13 3% and 29 5% between the middle layer and the lower layer in the growth duration. At early stage,the nitrogen content gradually increased with the increasing of the nitrogen application. But there were stable nitrogen gradient between different layers. There appeared greater nitrogen content gradient at middle and latter growth stage and the gradient sharpening with the nitrogen application amount. The vertical distribution property of Chl(a b) concentration was similar to that of the nitrogen. But there were greater gradient of Chl(a b) concentration than that of nitrogen content between upper and middle layer and less between middle and lower layer. The amount of nitrogen application decreased the Chl(a b) gradient between middle and lower layer,which differ from that of nitrogen. Under the lower nitrogen condition,there existed significant reflectance difference among different layer at the red wavebands,the wavebands from 1400nm to 1800nm and from 1950nm to 2300nm.The reflectance of lower layer was significantly higher than that of upper and middle layer. But there was almost no difference among different layer with affluent nitrogen application. There was apparent gradient distribution in different layer and appeared gradually decreased from upper to lower layer at near infrared platform. But the amount of nitrogen application didn't affect the gradient distribution characteristics of spectral reflectance. Besides,the correlative coefficients between canopy spectra and foliar biochemical contents of different layers were analyzed. The canopy spectral reflectance in different bands for remote sensing of foliar biochemical contents in different layers were found,and the spectral reflectance is significant correlative with foliar Chl(a b) content of middle and lower layers. Future work should involve giving more attention on the method for multi angle analyzing and establishing inversion model.
%K winter wheat
%K nitrogen content
%K vertical distribution
%K spectrum<br>冬小麦
%K 氮素
%K 垂直分布
%K 反射光谱
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&jid=F926358B31AC94511E4382C083F7683C&aid=372EF2105A54DAE5&yid=D0E58B75BFD8E51C&vid=5D311CA918CA9A03&iid=E158A972A605785F&sid=F637763636425CAF&eid=EC34D52BE81085CE&journal_id=1007-4619&journal_name=遥感学报&referenced_num=22&reference_num=12