Combining satellite data for estimation of rainfall for analysis of a watershed scale

The microwave/infrared rainfall algorithm (MIRA) method combines microwave and infrared channels for their respective contributions to the achievement of higher rainfall-correlated and spatial resolution data, in order to acquire appropriate rainfall data for hydrological models. In this study, estimates of rainfall rate using the MIRA method are affected by the time lag between the data acquisition of the microwave and infrared channels. The root-mean-square error (RMSE) for comparing the rainfall rate retrieved by the MIRA method (5-minute time lag between microwave and infrared data) to the ground rainfall rate in Taiwan is 12.23 mm hour(-1) with a correlation coefficient of 0.58. In addition, by comparing rainfall estimated by the TMI-2A12 and the MIRA method for three typhoons, the rainfall estimated by the latter method is more significantly correlated with the ground-observed rainfall.