GPM Core Observatory satellite was launched in February 2014. GPM Core Observatory satellite is equipped with the Dual-frequency Precipitation Radar (DPR), the DPR consists of a Ku-band precipitation radar (KuPR) and a Ka-band precipitation radar (KaPR). KuPR is a successor of TRMM/PR, and both have the same design. However, differences have been confirmed in their estimates for the same rainfall. Therefore, we focus on the retrieval method of rainfall rate and compare the rainfall rate estimates by KuPR and PR. Also we focus on the surface reference technique (SRT) and observation time lag to consider the factors of differences.
