摘要
灰尘作为气溶胶的一部分由于沉降现象而附着于植物叶子的表面,当遥感探测器扫描植被冠层时,所得反射率数据就具有了一定的相似性。在平时我们处理卫星数据时忽略了附着于叶子表面灰尘的影响,没有把植被表面的灰尘作为影响因子考虑进去。随着探测器的发展,光谱分辨率的提高,灰尘对于某些波段的影响越来越大。由于天气变化如降雨可以使植被叶片表面灰尘减少甚至消失,引起植被反射率发生变化,于是本文通过模拟降雨前后植被叶片反射率变化,来研究灰尘的影响程度大小。具体方法为采用ASD野外光谱仪分别测量小麦、冬青等植被采摘后表层附有灰尘的叶片和模拟雨水冲洗灰尘后的叶片。通过同一片叶子两次测得的不同数据处理、比较得出以下结论:1.附着于植被冠层的灰尘对其反射率有很大影响。2.没有去尘处理的叶片反射曲线不是灰尘反射曲线和经除尘处理的叶片反射曲线简单的线性叠加。3.灰尘并不会造成“红边”移动,不会发生“蓝移”和“红移”。
As a part of the aerosol, dust will cling to the surface of the foliage when the dust precipitates from aerosol. Just because of the covered dust, when the satellite sensors scanning vegetation canopy, the reflectance data that the sensors obtained will get similar. Even more, the weather changes will make for amount of the dust that covered the leaves increasing or decreasing, for example there is a distinct different between effect of dust before and after raining. So far we still ignore the effect of the dust that covered the leaves＂ surface when we process the remote sensing data. As the sensors developed the sensitivity of the sensors to detecting the electromagnetic radiation becomes higher and higher, will the effect of dust not be changed with the development of sensors？ We must assess the effect of dust on foliage reflectance anew. In this paper we use ASD FieldSpec to measure winter wheat and Rohdea japonica leaves. First we measure the leaves with dust on their surface, then rush out the dust and measure the leaves again. Compare the two measurements, we find that the dust effect leaves reflectance, and the leaves red edge position doesn＇t move.
出处
《中国农学通报》
CSCD
2007年第4期410-414,共5页
Chinese Agricultural Science Bulletin
基金
农业部引进国际先进农业科学技术专项资金项目(948项目)"高光谱农作物识别
长势分析与信息处理系统"(2001-245)。
关键词
反射率
灰尘
植被冠层
光谱
Red edge position, Dust, Reflectance, Canopy
作者简介
肖伸亮，男，1979年出生，河北定州人，硕士研究生，主要从事农业遥感应用研究，Tel：13691040719，E-mail：shlxiao@163．com。
通讯作者：陈仲新，男，1970年出生，河北唐山人，研究员，博士，主要从事GIS及遥感农业应用、信息农业和数字农业、农业生态等方面的科研工作。通信地址：100081 北京市海淀区中关村南大街12号中国农科院农业资源与农业区划研究所。
