Fig. 7From: Method for accurate multi-growth-stage estimation of fractional vegetation cover using unmanned aerial vehicle remote sensingUAV-based VNAI–SI 2-D scatter maps for stage S4. a VNAI–NDVI, b VNAI–NDVI2, c VNAI–RDVI, d VNAI–SAVI. Note: Red dots represent the 120 ROIs from Fig. 1cBack to article page