The Quantitative Inversion and Space-Time Variety Analysis of VWC Based on the Remote Sensing Spectrum

The paper primary makes certain some bands or band combination as the RS spectral indices of vegetation water content based on analyzing the vegetation spectral characteristics and the relativity between spectrum and vegetation water content. With the ground survey data, the best function models are respectively established between the vegetation water content and spectral indices. Based on analyzing the different functions of the spectral index and its relative error RE, The paper confirms the spectral index ^SR=R ₁₆₀₀ ^/R ₈₂₀ as the characteristic parameters of the vegetation water content model in this study area. The monitoring model is established between VWC and SR spectral index, and the correlative physics parameters are educed by the means of RS spectrum and math statistics. According to the RS monitoring model of vegetation water content, ETM and ASTER remote sensing data, the quantitative inversion of vegetation water content were achieved by the program based on IDL7.0 platform. The measured data and background data surveyed in the study area is used to evaluate and analyze synthetically the inversion results. The study results show that the SR spectral index can eliminate the outside impact of the background environment, the canopy structure, and other factors. The precision of remote sensing inversion of vegetation water content is superior. It can truly reflect the time and space variety characteristics of the vegetation water content in the study area.