Yield Estimation by Hyperserctral Data of Rice Canopies in Mature Stages

Two cultivars of rice were used in field experiment under 3 nitrogen application levels. The hyperspectral reflect- ances of their canopies,flag leaves and panicles were measured by a ASD FieldSpec Pro FR TM in different stages after heading. The leaf area indices ( LAI ) corresponding to the hyperspectral reflectance,and the ultimate theoretical yield and real yield were determined. The correlation between the yields and the hyperspectral data,LAI of rice were analyzed. With the growth and development of rice,the spectral reflectance of the canopy were gradually getting bigger in the visible region and smaller in the near infrared region. The theoretical yield and real yield were very significantly correlated with the hyperspectral difference vegetation indices R 1200 - R 680 ,R 990 - R 680 ,R 800 - R 680 ,R 1200 - R 550 ,R 990 - R 550 ,R 800 - R 550 ,R 1200 - R 440 ,R 990 - R 440 , R 800 - R 440 ,the red edge amplitude D λ red and red edge area S red . They also were very signifi- cantly correlated with LAI . The results suggested that the rice yield would be estimated by hyperspectral remote sensing. The best accuracy was above 95% in yield estimation with hyperspectral vegetation index R 1200 - R 440 and R 990 - R 440 .