Table 6.

Variation of surface temperature (T_s), normalised difference vegetation indeed (NDVI) and daily evapotranspiration (ET) over the Volta savannah from MODIS & AATSR sensors (N = 71 pixels).

Date of image acquisition [Julian day]	Landsat ETM+	MODIS			AATSR
	050104 [05]	131104 [318]	021204 [337]	250105 [25]	131104 [318]	021204 [337]	250105 [25]
Land Surface Temperature (Ts)
Maximum	312.451	309.476	309.650	310.390	317.037	323.089	322.356
Minimum	286.318	302.078	302.616	306.691	308.623	308.750	312.347
Mean	301.869	304.383	306.217	308.586	312.463	318.970	319.050
Std. Deviation	7.091	1.594	1.999	0.965	1.871	2.890	1.882
NDVI
Maximum	0.809	0.727	0.720	0.661	0.751	0.701	0.693
Minimum	0.025	0.387	0.326	0.312	0.519	0.461	0.488
Mean	0.521	0.620	0.566	0.489	0.639	0.587	0.582
Std. Deviation	0.083	0.066	0.079	0.068	0.045	0.074	0.046
Daily Evapotrans piration (ET 24)
Maximum	8.510	2.297	3.082	2.831	0.987	1.471	0.706
Minimum	0.000	0.020	0.025	0.904	0.000	0.300	0.000
Mean	3.102	0.918	1.469	2.052	0.283	0.965	0.170
Std. Deviation	1.424	0.609	0.840	0.400	0.213	0.282	0.140