One of the prime instruments onboard the GPM Core Observatory is called the Dual-frequency Precipitation Radar (DPR). The DPR consists of a Ku-band precipitation radar (KuPR) and a Ka-band precipitation radar (KaPR). The KuPR (13.6 GHz) is an updated version of the highly successful unit flown on the TRMM mission. The KuPR and the KaPR are co-aligned on the GPM spacecraft bus such that that the 5 km footprint location on the earth is the same.
Data collected from the KuPR and KaPR units provides 3-dimensional observations of rain and also provides an accurate estimation of rainfall rate to the scientific community. The DPR instrument is allocated 190 Kbps bandwidth over the 1553B spacecraft data bus.
Learn more: https://pmm.nasa.gov/GPM/flight-project/DPR