Journal of Sensors

Research Article

Remote Sensing of Grassland Biophysical Parameters in the Context of the Sentinel-2 Satellite Mission

Table 4

Summary of the statistics (: number of observations; Adj. : adjusted coefficient of determination; : cross-validated Adj. ; RMSE: root mean square error; RMSE: cross-validated RMSE; NMRSE: normalized RMSE; NRMSE: cross-validated NRMSE) of the linear regression (model 1) between both fraction of photosynthetically active radiation absorbed by vegetation canopy (FAPAR) and fraction of photosynthetically active radiation absorbed only by photosynthesizing canopy components (GFAPAR) and spectral vegetation indices (VIs) considering both years of observation (2014 and 2015). The three best-fitting models in each group are printed in bold. The best performing model is additionally highlighted in italic. Asterisk indicates significance of correlation: ; ; ; n.s.: not significant (Pearson’s correlation test).


Model	VI	FAPAR estimation statistical summary							GFAPAR estimation statistical summary
			Adj.		RMSE	RMSE	NRMSE	NRMSE		Adj.		RMSE	RMSE	NRMSE	NRMSE
		—	—	—	—	—	—	—	—	—	—	—	—	—	—

1	NDVI	94	0.07	0.03	0.16	0.16	0.23	0.24	94	0.66	0.64	0.11	0.12	0.15	0.15
	GNDVI		0.18	0.15	0.15	0.15	0.22	0.22		0.66	0.65	0.11	0.11	0.15	0.15
	RENDVI		0.04	0.00	0.16	0.17	0.23	0.24		0.74	0.72	0.10	0.10	0.13	0.13
	MTCI		0.01	0.00	0.16	0.17	0.24	0.24		0.77	0.76	0.09	0.09	0.12	0.12
	RECI		0.05	0.02	0.16	0.16	0.23	0.24		*0.78*	*0.77*	*0.09*	*0.09*	*0.12*	*0.12*
	GCI		*0.18*	*0.15*	*0.15*	*0.15*	*0.22*	*0.22*		0.67	0.65	0.11	0.11	0.15	0.15
	WDRWI		0.08	0.05	0.16	0.16	0.23	0.23		0.74	0.73	0.10	0.10	0.13	0.13
	EVI		0.02	0.00	0.16	0.17	0.24	0.24		0.72	0.71	0.10	0.10	0.13	0.14
	NDWI		0.03	0.00	0.16	0.17	0.24	0.24		0.64	0.62	0.12	0.12	0.15	0.16