CAJ | 학술논문

实践中,大尺度卜测量叶面积指数(LAI)很难实现,利用遥感技术进行LAI的定量反演成为当前研究的重点.该文应用MODIS地表反射率数据反演冬小麦叶面积指数,假设MODIS像元由作物和土壤混合,建立了SAILH模型与裸土反射率组成的线性光谱混合模型,基于人工神经网络的方法进行LAI反演,获得了北京顺义冬小麦种植区在2001年4月1个时间序列的LAI.研究表明,此方法能够较好的获取大区域尺度上的LAI,对冬小麦长势监测具有重要意义.
실천중,대척도복측량협면적지수(LAI)흔난실현,이용요감기술진행LAI적정량반연성위당전연구적중점.해문응용MODIS지표반사솔수거반연동소맥협면적지수,가설MODIS상원유작물화토양혼합,건립료SAILH모형여라토반사솔조성적선성광보혼합모형,기우인공신경망락적방법진행LAI반연,획득료북경순의동소맥충식구재2001년4월1개시간서렬적LAI.연구표명,차방법능구교호적획취대구역척도상적LAI,대동소맥장세감측구유중요의의.
In practices, measuring leaf area index (LAD in large area scale is very difficult. Therefore, retrieving LAI quantitatively based on remote sensing technology is concerned by many researchers. We proposed a BP-ANN based method to retrieve winter wheat LAI using surface reflectance data of MODIS. The MODIS pixel is assumed to be composed by crop canopy and bare soil. The SAILH (Light Scattering by Arbitrarily Inclined Leaves including the Hotspot-effect) model was used to simulate the directional reflectance of crop canopy, and the bare soil was assumed to be Lambertian. Series LAI maps of winter wheat in Shunyi District, Beijing were retrieved using this method during April in 2001. The research indicated that this method can be used well to retrieve LAI in large area scale, which is valuable to monitor crop growth.