Simulation Research in A Two-layer Canopy Reflectance Model

摘要

In this paper, a theoretical simulation of A new two-layer Canopy Reflectance Model (ACRM) is explored. Based on the ACRM model, canopy reflectance angular distributions with wavelength 820nm and 1600nm are simulated under the influence of LAI (leaf area index), Cw (water content)and N (a leaf structural parameter). Research results indicate that the hot spot effect can be simulated precisely. The sensitivity of canopy reflectance angular distributing to LAI is less than to LAI-Cw and LAI-N. Reflectance angular distribution at wavelength of 1600nm is strongly related to LAI and Cw while reflectance angular distribution at wavelength of 820nm is appreciable larger than 1600nm under LAI and N effect. Otherwise, using information contained in near-infrared (820nm)and short-wave infrared (1600nm) canopy reflectance we proposed a soil-adjusted water index which is employed to retrieve the canopy water content is also greatly influenced by canopy structure. Canopy structure is worth considering in the process of model selection henceforth.