The Evaluation of GPM Precipitation Remote Sensing Data with Observed Data (Case Study: Mid-West of Iran)

One of the most important problems of researchers in atmospheric and hydrological studies is sometimes the lack of accurate and up-to-date data. In many mountainous and desert areas, synoptic stations and rain gauges are not distributed at the right distance. Therefore, the use of satellite data recorded by rainfall can be a good complement to the lack of this type of data. The purpose of this study is to evaluate the accuracy of satellite data versus observational data. In this study, the daily rainfall data recorded by the GPM sensor with a resolution of 0.1 0.1 in the Midwest of Iran for 691 days in the period from 12/3/2014 to 31/1/2016 has been investigated. For this purpose, the daily precipitation data of 31 synoptic stations were used as observational data, and the statistical indices R, EF, IA, slope, bias, Rmse were used to evaluate the data. The results showed that 74% of the stations had a strong correlation of 0.8-0.5. But based on over-estimated and underestimated indicators, it was found that the GPM sensor has a low precipitation rate of 58% of the stations, Also, for stations in the province of Kermanshah (with the exception of the Kengawer, which has a bias of zero), there is an over estimated rainfall.