基于TM和MODIS数据的滇中地区云南松林反射光谱特征分析

Analysis of Reflectance Spectra Characteristics of Pinus yunnanensis based on TM and MODIS in Central Yunnan,China

以云南省滇中地区为研究区,以2007年云南松样地一类清查结果为基础数据,获取样地测树因子信息。以Landsat、MODIS卫星遥感图像为光谱信息提取数据源,获得多光谱遥感图像的光谱值,并分不同坡向、郁闭度等级和不同分辨率等级绘制成滇中云南松的反射光谱曲线。结果表明,滇中地区的云南松主要分布影像在红外波段部分,曲线变化特征及反射率值比TM像反射率值阴坡大于阳坡;不同郁闭度等级提取的云南松反射率值,TM和MODIS的结果均为:密<中<疏,郁闭度相对坡向而言,对云南松反射率值的影响更大。

Taking the central Yunnan Province as the research area,based on the survey results of Pinus yunnanensis sample plots in 2007,the tree survey factor information of sample plots was obtained.Using Landsat and MODIS satellite remote sensing images as spectral information extraction data sources,the spectral values of multispectral remote sensing images were obtained,and the reflective spectral curves of Pinus yunnanensis in central Yunnan were plotted according to different slope orientation,canopy density and resolution levels.The results show that Pinus yunnanensis mainly distributes on the sunny slope,but the canopy density on the shady slope is higher and the stand is more mature;TM image has more obvious spectral characteristics in the visible part,MODIS image in the infrared part,curve change characteristics and reflectance value are closer to the true value than TM image;TM image reflectance value on the shady slope is smaller than that on the sunny slope,and MODIS image reflectance value on the shady slope is larger.The results of TM and MODIS for reflectivity of Pinus yunnanensis extracted from different canopy closure grades were as follows:density<medium<sparse,canopy closure had greater impact on reflectivity of Pinus yunnanensis than slope direction.