Influence of Vegetation Index on LAI Inversion Accuracy at Different Bandwidths

The vegetation indices (VIs) have been widely used to invert the leaf area index (LAI), but in the process of inversion, the accuracy of inversion is often affected by various parameters. Based on the canopy spectral reflectance simulated by the PROSAIL model, 15 vegetation indices that are commonly used for LAI inversion and have a higher mean coefficient of determination (R²) with LAI are screened. By analyzing the sensitivity of vegetation index to bandwidth and the relationship between R² and bandwidths, the influence of bandwidth on the accuracy of vegetation index inversion LAI is discussed. The results show that the accuracy of estimating LAI by vegetation indices is greatly affected by bandwidth. In addition, it is found that there is some optimal bandwidth for vegetation index.