[A study on multicomponent bidirectional reflectance model for rice].

Abstract

In this paper, the bidirectional reflectance factor (BRF) of rice measured in field experiment in 1999 and 2000 was compared with the BRF computed from the rice multicomponent bidirectional reflectance model that based on the radiative transfer theory, rice canopy geometric structural factors and different characteristics of the different growth period for rice in detail. The contribution of some sensitive factors such as the average inclination angle of all components belonged to rice and LAI was accurately specified. The results showedthat the rice multicomponent bidirectional reflectance model described above could basically simulate the angular distribution characteristic of reflectance spectrum of rice canopies, and the different peak point of the hotspot effect of rice canopies reached under different conditions. In addition, the regulation of the first-order scattering reflectance by soil and water and the multiple scattering reflectance by foliage, stem, fringe and soil changing with the average inclination angle of all components, as well as the contribution of LAI to BRF were analyzed. All of these laid a foundation to monitor rice growth and estimate its yield. Meanwhile, it also implied that some rice canopy parameters could be accurately estimated by the model through selecting the suitable image bands.