Evaluation of the performance of daily satellite-based rainfall (CMORPH, CHIRPS, GPM IMERG, and TRMM) was done to obtain applicable satellite rainfall estimates in the groundwater basin of the Merapi Aquifer System (MAS). Performance of satellite data was assessed by applying descriptive statistics, categorical statistics, and bias decomposition on the basis of daily rainfall intensity classification. This classification is possible to measure the performance of daily satellite-based rainfall in much detail. CM (CMORPH) has larger underestimation compared to other satellite-based rainfall assessments. This satellite-based rainfall also mostly has the largest RMSE, while CHR (CHIRPS) has the lowest. CM has a good performance to detect no rain, while IMR (GPM IMERG) has the worst performance. IMR and CHR have a good performance to detect light and moderate rain. Both of them have larger H frequencies and lower MB values compared to other satellite products. CHR mostly has a good performance compared to TR (TRMM), especially on wet periods. CM, IMR, and TR mostly have a good performance on dry periods, while CHR on wet periods. CM mostly has the largest MB and lowest AHB values. CM and CHR have better accuracy to estimate rain amount compared to IMR and TR. All in all, all 4 satellite-based rainfall assessments have large discrepancy compared with rain gauge data along mountain range where orographic rainfall usually occurs in wet periods. Hence, it is recommended to evaluate satellite-based rainfall with time series of streamflow simulation in hydrological modeling framework by merging rain gauge data with more than one satellite-based rainfall than to merge both IMR and TR together.

对基于卫星的每日降雨量（CMORPH、CHIRPS、GPM IMERG 和 TRMM）的性能进行了评估，以获得适用于默拉皮含水层系统 (MAS) 地下水盆地的卫星降雨量估计值。在日降雨强度分类的基础上，通过应用描述性统计、分类统计和偏差分解来评估卫星数据的性能。这种分类可以非常详细地测量每日基于卫星的降雨的性能。与其他基于卫星的降雨评估相比，CM (CMORPH) 具有更大的低估。这种基于卫星的降雨也大多具有最大的RMSE，而 CHR (CHIRPS) 最低。CM检测无雨性能较好，而IMR（GPM IMERG）性能最差。IMR和CHR在检测小雨和中雨方面有很好的性能。与其他卫星产品相比，它们都具有更大的H频率和更低的MB值。与 TR (TRMM) 相比，CHR 大多具有良好的性能，尤其是在潮湿时期。CM、IMR 和TR 大多在干旱期表现良好，而CHR 在湿润期表现良好。CM 大多具有最大的MB和最低的AHB值。与 IMR 和 TR 相比，CM 和 CHR 具有更好的降雨量估计精度。总而言之，与地形降雨通常发生在潮湿时期的山脉的雨量计数据相比，所有 4 项基于卫星的降雨评估都有很大的差异。因此，建议通过将雨量计数据与多个基于卫星的降雨量合并而不是将 IMR 和 TR 合并在一起，来评估基于水文建模框架中的水流模拟时间序列的基于卫星的降雨量。