利用风云卫星MERSI数据反演叶面积指数的研究

风云三号A星上搭载的中分辨率成像光谱仪(Medium Resolution Imaging Spectrometer)MERSI从2008年5月底开始对地球观测,其中5个波段250m分辨率的数据包含了丰富的植被信息,在全球同类传感器数据中独具特色,在其基础上反演的陆表植被数据产品目前还不多见。利用2013年生长季在河北固城观测获取的冬小麦光谱数据,结合MERSI 250m数据计算的NDVI值,建立二者NDVI之间的线性转换模型Y=1.1458 X+0.1916;同时利用地物光谱NDVI与实测叶面积指数构建了NDVI-LAI指数模型Y=0.0899e4.459 X;然后,利用MERSI 250m数据反演出华北太行山前平原区冬小麦的叶面积指数,经与大田观测的叶面积指数以及同期MODIS的叶面积指数产品对比验证,结果表明:反演的MERSI-LAI与实际观测叶面积指数接近且具有很好的线性关系,其空间分布与MODIS的叶面积指数相近,但MODIS-LAI数值明显偏小。

Inversion of Leaf Area Index Using the MERSI Data of the Feng Yun Satellite

The data of the Medium Resolution Imaging Spectrometer (MERSI) on board FY\|3A were made available since the end of 2008.It provides the data with five bands at 250 meter resolution,which captures abundant vegetation information and is a unique data source of the similar sensors in the world.However,few literatures reported the utilization of these data.In this paper,we used the spectral data during the growing season of winter wheat in Gucheng experiment site,Hebei province in 2013,to calculate the vegetation index,and combined with the NDVI data which calculated from the 250 meter MERSI data,to establish a linear transformation model Y=1.1458X+0.1916 between the two NDVIs.At the same time,we used the spectral NDVI and the measured leaf area index to establish a NDVI\|LAI conversion model Y=0.0899e4.459X.Then,we used the 250 meter MERSI data to retrieve the leaf area index for Taihang piedmont area of winter wheat.Finally we compared the results with the observed LAI in the field and the MODIS\|LAI product in the same period.The result shows that,there is a good exponent relationship between the leaf area index retrieved from MERSI\|NDVI data and the observed LAI in the field,and then its spatial distribution was similar with MODIS-LAI,but MODIS\|LAI was significantly smaller.