Fig. 6

Scatterplots of multivariate Gaussian process regression (MGPR) predictions of species-specific tree volumes (m3/ha). Grey dots are produced by the MGPR models where, in addition to structural features, red–green–blue (RGB) data were used. Black crosses are produced from the MGPR models where multispectral (MS) data were used in addition to structural features. The predictions are the average predicted value of 10-fold cross-validation iterated 100 times. Dashed line is the 1:1 line