H-SAF Product Validation Report (PVR) PR-OBS-3

Products Validation Report, 30 May 2010 - PVR-03 (Product PR-OBS-3) Page 48
4.5 Validation in Italy (UniFe)
The facilities available to the University of Ferrara, and the methodology adopted for validation, are
described in section 3.4.4. The ground truth is provided by rain gauge networks.
Table 11 reports the results of the final validation campaign of the Development Phase for PR-OBS-3.
Table 11 - Summary results of PR-OBS-3 validation in Italy by UniFe
H03 v1.4 Italy Land Validation period: 1 st January 2009 - 31 March 2010 - Threshold rain / no rain: 0.25 mm/h
Gauge Class Jan Feb Mar Apr Mag Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar
Number of > 10 mm/h 15688 4719 8568 8229 4778 11360 8496 5231 21935 11638 11828 8189 8678 6694 4527
comparisons 1-10 mm/h 463330 310536 374752 404578 79968 190186 75707 71910 243353 205628 315887 429933 429878 441610 288645
(ground obs.) < 1 mm/h 480462 339540 350497 385169 93567 185437 63285 75866 203657 210846 299523 485470 524200 533291 365103
> 10 mm/h -15.9 -15.7 -18.5 -13.8 -16.9 -15.1 -15.5 -14.4 -14.8 -13.7 -14.2 -14.2 -14.9 -14.5 -14.7
ME (mm/h) 1-10 mm/h -2.31 -2.30 -2.39 -2.28 -2.17 -2.04 -2.06 -2.23 -1.74 -2.01 -2.43 -2.34 -2.30 -2.24 -1.95
< 1 mm/h -0.40 -0.48 -0.44 -0.31 -0.13 -0.04 0.17 -0.02 0.23 -0.24 -0.29 -0.44 -0.43 -0.41 -0.31
> 10 mm/h 9.38 9.61 15.0 5.96 10.1 7.67 9.15 6.82 9.67 11.5 6.56 7.59 8.13 8.42 8.25
SD (mm/h) 1-10 mm/h 1.77 1.56 1.77 1.85 2.26 2.36 2.76 2.44 3.50 2.89 2.04 1.67 1.71 1.69 1.68
< 1 mm/h 0.48 0.33 0.48 0.69 1.18 1.13 1.43 1.22 2.24 1.26 0.69 0.39 0.49 0.45 0.67
> 10 mm/h 18.5 18.4 23.9 15.0 19.7 16.9 18.0 15.9 17.7 17.9 15.6 16.1 16.9 16.8 16.8
RMSE (mm/h) 1-10 mm/h 2.92 2.78 2.98 2.94 3.13 3.12 3.45 3.30 3.91 3.52 3.17 2.87 2.87 2.81 2.58
< 1 mm/h 0.63 0.58 0.65 0.75 1.18 1.13 1.44 1.22 2.25 1.28 0.75 0.59 0.65 0.61 0.74
> 10 mm/h 95 96 98 97 94 92 90 93 89 87 96 96 97 98 96
RMSE (%) 1-10 mm/h 93 96 96 93 104 99 105 100 148 121 92 94 96 .94 92
< 1 mm/h 119 104 123 156 272 254 325 275 505 264 159 109 127 114 152
> 10 mm/h 0.02 0.04 -0.15 0.01 0.01 0.12 0.02 0.05 0.04 0.01 -0.03 -0.02 -0.07 -0.07 -0.10
CC 1-10 mm/h 0.19 0.19 0.10 0.10 0.11 0.11 0.08 0.10 0.11 0.19 0.09 0.17 0.12 0.09 0.09
< 1 mm/h 0.06 0.05 0.04 0.05 0.03 0.04 0.05 0.05 0.04 0.05 0.08 0.05 0.04 0.06 0.06
POD ≥ 0.25 mm/h 0.19 0.10 0.12 0.24 0.26 0.37 0.43 0.35 0.39 0.254 0.27 0.15 0.13 0.17 0.24
FAR ≥ 0.25 mm/h 0.43 0.48 0.53 0.57 0.76 0.63 0.56 0.70 0.49 0.55 0.48 0.49 0.47 0.52 0.53
CSI ≥ 0.25 mm/h 0.17 0.09 0.11 0.19 0.14 0.23 0.28 0.19 0.28 0.194 0.22 0.13 0.11 0.14 0.19
An overall indication of the capabilities of a satellite technique to reproduce a precipitation field is given
by the comparison between estimated and measured probability density functions (PDF) of the rainrate
values, sampled at 1 mm h -1 , starting from 0.25 mm h -1 . In Fig. 39, PDF for estimated and reference
rainrates for January (left panel) and July (right panel) 2009 are shown in order to also highlight
seasonal features.
Fig. 39 - Probability Density Function for the months of January (left) and July (right) 2009.
For the winter precipitation, as described by January plot, the estimated PDF is constantly below the
measured one, indicating the relative abundance of no-rain estimates (below 0.25 mm h -1 ), not