Evaluation and Comparison of GPM Satellite Precipitation Data with Meteorological Station using Kolmogorov-Smirnov Test

This study aimed to evaluate and compare the estimated rainfall of GPM meteorological satellite with ground stations using non-parametric Kolmogorov-Smirnov in Gorganrood catchment, Golestan province. In this study, 16 stations were used with the statistical period of 20.03.2014 -20.03.2016. The daily rainfall data of the GPM satellite with a spatial resolution of 0.1 degrees were collected. Data analysis was performed in the MATLAB environment. The results showed that ​​in Bagh Salian, Dashte Shad, Ghochamz, Hagh-ol-Khaje, Zaringol stations, the P-value ​​were higher than the α significance level and were 0.83, 0.36, 0.11, 0.95, 0.33, respectively. Therefore, it showed that the difference between satellite precipitation data and ground station observations was not significant. The results also showed that (0.95) P-value was the highest correlation of GPM data with observational records in Hagh-ol-Khaje station. The lowest level of compliance with the value of 0.001 is related to Shirabad station. Therefore, to improve GPM satellite products, especially in watersheds with the wide spatial distribution and temporal variations of precipitation, calibration of satellite precipitation products should be on the agenda to improve their accuracy in measuring daily precipitation. The Kolmogorov-Smirnov test was performed for the first time to examine the correlation of daily GPM satellite data with observational data, and there was a relative correlation between satellite data and observed ground station records in all stations where the H0 hypothesis was accepted