A Simple Semi-Empirical Model for the Estimation of Photosynthetically Active Radiation from Satellite Data in the Tropics

Table 3

Root mean square difference (RMSD) and mean bias difference (MBD) obtained from the comparison between calculated and measured monthly average hourly PAR values.

Time	Chiang Mai		Ubon Ratchathani		Nakhon Pathom		Songkhla		Combined data
	MBD (%)	RMSD (%)	MBD (%)	RMSD (%)	MBD (%)	RMSD (%)	MBD (%)	RMSD (%)	MBD (%)	RMSD (%)
8:30	−13.5	26.9	−0.2	10.1	−7.1	13.6	−12.4	13.9	−8.2	16.8
9:30	−9.0	14.2	1.2	9.4	−3.5	8.3	−9.8	12.9	−5.6	11.5
10:30	−8.7	15.8	1.0	6.3	−2.7	6.7	−12.2	13.2	−6.1	11.4
11:30	−2.3	5.3	0.6	7.5	−1.3	6.0	−8.9	10.5	−3.2	7.8
12:30	−2.2	5.6	1.8	8.4	−0.9	6.5	−10.5	11.9	−3.2	8.7
13:30	−2.2	6.0	1.8	9.4	0.0	5.9	−8.0	9.4	−2.5	7.9
14:30	−5.9	12.9	8.9	13.3	−1.3	6.3	−5.3	6.6	−1.9	9.6
15:30	−7.3	11.1	−2.4	20.1	−4.4	11.2	−12.3	12.9	−6.7	13.7
16:30	−18.9	24.2	−11.6	16.6	−15.3	18.8	−22.6	24.9	−17.5	22.3
All hours	−6.6	12.6	0.8	10.6	−3.0	8.2	−10.4	12.3	−5.1	11.1