Ahmet Öztopal, Albero Mugnai, Daniele Casella, Marco ... - H-SAF

A third case study example is shown in Figure 5.16 concerning the radar andretrieval (model estimation data scatter diagrams correspondingly for 21 March 2008 at18:07 GMT. Both one-cell and 3-cell averaging (filtering) schemes have almost the samescatter on both Cartesian coordinate systems. In fact, it is very clear in Figure 5.16b thatthere is a non-linear relationship between the two sets of values. This is tantamount tosaying that the proposed model cannot depict the variation feature between the retrievaland radar measurements.25y = 0.4054x + 0.6505R 2 = 0.342410y = 0.5582x + 0.5549R 2 = 0.5655Rain Rate Radar (mm/hr)2015105Rain Rate Radar (mm/hr)8642a00 5 10 15 20 25Rain Rate Retrieval (mm/hr)b00 2 4 6 8 10Rain Rate Retrieval (mm/hr)Figure 5.16. Scatter diagrams between radar and retrieval on 21 March 2008 at 18:07GMT (a) original comparision, (b) after applying a 3X3 filter.Table 5.10 is for the statistical quantities and Table 5.11 is for categorical statistics.Both statistical quantities and categorical statistics are good.Table 5.10. Statistical features (21 March 2008 at 18:07 GMT)Statistics 1X1 filter 3X3 filterMean Error 0.51 0.23Mean absolute error 1.42 0.97Mean squared error 7.68 3.05Root mean square error 2.77 1.75Standard deviation 2.73 1.75Correlation coefficient 0.59 0.75(Multiplicative) bias 1.35 1.15URD-RMSE 13.63 59.24Table 5.11. Rainfall occurrence indices (21 March 2008 at 18:07 GMT)Categorical Statistics 1X1 filter 3X3 filterPOD 0.67 0.71BIAS 0.70 0.75FAR 0.05 0.05CSI 0.64 0.69HR 0.84 0.82POFD 0.03 0.0423