VALIDASI PRODUK SATELIT GPM-IMERG (IMERG EARLY, IMERG LATE, DAN IMERG FINAL) DI WILAYAH PULAU SUMATERA TAHUN 2019-2020

Abstract

Rainfall is one of the meteorological parameters that play an important role in understanding weather conditions. However, the incompleteness of rainfall data become obstacles in assessing rainfall. Rainfall estimation using satellite remote sensing can be a solution for this problem. The GPM-IMERG satellite is a satellite specially designed to estimate rainfall which has three main products, that is IMERG-E, IMERG-L, IMERG-F. This study aims to validate GPM-IMERG satellite products by reviewing the satellite's ability to detect rain events, statistical distribution analysis, and diurnal cycle analysis with the research area on the island of Sumatra with different altitude categories. The results of the analysis of the ability to detect rainfall showed that the IMERG-L and IMERG-F products gave better results than the IMERG-E products in all altitude categories, namely coastal, low, and high with a range of POD values of 0.4-0.8 as for the FAR and CSI are 0.8 and 0.1. Then from the statistical distribution analysis using Taylor diagrams and QQ plots, it shows that the estimated results of the three GPM-IMERG satellite products overestimate the rainfall observation data and it is also seen that the IMERG-F product gives consistently better results than the other two products.