Topographic Correction of Zy-3 Satellite Image and Its Effects on Estimation of Shrubs Leaf Biomass in Mountainous Area

In this paper, the authors rectified ZY-3 satellite data with a total of 5 commonly used topographic correction models, and investigate its impact on the regression fitting estimation of shrub forest leaf biomass in the study area. Through visual inspection, statistical analysis and correlation analysis to evaluate every result of the correction models, and the result shows that Minnaert +SCS model based on the non-lambertain reflection assumption is supposed to be the most befitting correction for the ZY-3 image in the study area, moreover, to some extent, coefficient correlation of the biomass fitting result was improved after corrected, as well as the fitting precision. The R2 reached 0.869, while the standard error dropped to 72.7 g/m2, to be specific, the coefficient correlation of the model has increased by 0.113 while the precision has improved a range of 15.8g/m2. Therefore, the authors hold the opinion that in region of large relief, topographical correction is both indispensable and essential to the estimation of the biomass based on vegetation indices.