【摘要】 深入研究了PROSPECT模型中叶肉结构参数N对叶片反射和透射光谱的影响,利用迭代法使全波段代价函数达到最小来计算LOPEX93数据集中样品的最优N值,对在最优N值下的模拟光谱与实测光谱进行比较,并对N在不同取值情况下,叶绿素与水分的反演进行了研究.研究认为:(1)N对整个光谱波段产生影响,并随N的增大而减小;(2)构造全波段代价函数,利用迭代法得到的最优N值可以很好地模拟实际光谱;(3)在高估N值情况下的叶绿素和水分反演精度明显高于低估N值的情况;(4)水分反演的效果明显优于叶绿素反演的效果,原因与代价函数的选取有关.更多还原

【Abstract】 This paper presents an in-depth analysis on the influence of mesophyll structure parameter N in PROSPECT model on leaf reflectance and transmittance spectra. Optimal N values of samples in LOPEX93 data set are calculated by minimizing a whole-band cost function using the iterative method. Simulated spectra under calculated optimal N values are compared with measured ones. Further,inversions of chlorophyll and water content under different N values are performed. Results show that: (1) the influence of N involves the whole-band spectra from visible to near infrared,and the influence decreases with its values; (2) simulated spectra with optimal N ,which is calculated by minimizing a whole-band cost function using the iterative method,match very well with measured spectra; (3) the inversion accuracy of chlorophyll and water content by using overestimated N is better than that by using underestimated N ; (4) the inversion accuracy of water content is significantly better than that of chlorophyll partially due to the selection of cost function.更多还原