Aboveground Biomass Mapping of Crops Supported by Improved CASA Model and Sentinel-2 Multispectral Imagery

The net primary productivity (NPP) and aboveground biomass mapping of crops based on remote sensing technology are not only conducive to understanding the growth development but can also be used monitor timely agricultural information, thereby providing effective decision making for production management. To solve saturation problem NDVI in crops, original CASA model was improved using narrow-band red-edge which is sensitive vegetation chlorophyll variation, fraction photosynthetically active radiation (FPAR), NPP, winter wheat maize were mapped main growing seasons. Moreover, this study, we deeply analyzed seasonal change trends crops’ biophysical parameters terms NDVI, FPAR, actual light use efficiency (LUE), their influence biomass. Finally, analyze uncertainty further discussed inversion differences FPAR with different indices. results demonstrated that accuracies normalized index (NDVIred-edge) simple ratio (SRred-edge) higher than those model. Compared reference data, accuracy estimated by 0.73 0.70, respectively, 0.21 0.13 In addition, analysis inversions indices showed NDVIred-edge SRred-edge other indices, confirmed involving information more effectively retrieve crops.