Effect of Vertical Distribution of Crop Structure and Biochemical Parameters of Winter Wheat on Canopy Reflectance Characteristics and Spectral Indices

作者：Chunjiang Zhao, Heli Li, Pingheng Li, Guijun Yang, Xiaohe Gu, Yubin Lan · 发表于：IEEE Transactions on Geoscience and Remote Sensing · 年份：2016 · DOI：10.1109/tgrs.2016.2604492 · 被引用次数：47 · 研究领域：Remote Sensing in Agriculture、Leaf Properties and Growth Measurement、Land Use and Ecosystem Services

Vertical heterogeneity of the canopy is being increasingly recognized in remote estimates of vegetative properties. Given the current limited knowledge of this issue, this paper investigated the effects of different vertical distributions of crop structure [e.g., leaf angle (LA)] and leaf area index (LAI)] and biochemical parameters [e.g., chlorophyll a and b content (Chla+b) and water content (Wc)] on canopy reflectance and vegetation indices (VIs). A recently developed multiple-layer canopy reflectance model (MRTM) was tested for winter wheat and used to run a simulation analysis of different canopy scenarios. The results showed that the MRTM performed well to model winter wheat canopy reflectance with regard to spikes and vertical distributions of leaf properties. The vertical profiles of LA and LAI influenced canopy reflectance at almost all wavelengths, whereas the vertical profile of Chla+bmainly affected reflectance in the visible region, and that of Wconly affected reflectance in the near-infrared region. Changes in vertical distribution of the LA resulted in clear variations in VIs related to the LA, LAI, and Chla+bestimates. The vertical LAI and Chla+bprofiles mainly influenced the VIs related to the LAI and Chla+bestimates. The Wcvertical profile primarily affected the VIs used to estimate crop water properties. The sensitivities of the VIs were mainly associated with the spectral responses and penetration characteristics of the bands they used. These findings sugg...