The hydrological analysis is part of planning a water building. The availability of sufficient data as input data is important. However, there are still some data problems, such as the minimum number of years, incomplete data, or the number of stations is less evenly distributed. As technology develops, these problems can be solved by replacing ground-based observation data with satellite observations that have high spatial and temporal resolution, wide-area coverage, fast access, and economy. This research was conducted to validate and correct TRMM satellite data on observation data at the AWLR Gemawang station with the SCS Method. The results of the study showed that the average time lag of satellite and surface rainfall measurements was approximately 8.5 hours. Days of conformity index and efficiency analysis, TRMM satellite data got the correlation coefficient average ARR-AWLR discharge of 0.2416 which is categorized as lowefficiency data and TRMM-AWLR of 0.1041 which is categorized as quite low coefficient data, while efficiency coefficient gets average value 1.67 which is categorized as highly efficient optimization data. The results of the analysis of model errors can be concluded that TRMM rainfall data is still inaccurate, therefore it is necessary to increase accuracy. This is caused by the rain time lag that occurs between rain measurements of ARR and TRMM. The closer to the value of 0 (zero), the better the modeling results.