The Precipitation Rate (Final) layer is from the Integrated Multi-satellitE Retrievals for GPM (Global Precipitation Measurement) (IMERG) unified U.S. algorithm that provides the Day-1 multi-satellite precipitation product for the U.S. GPM team. The input precipitation estimates computed from the various satellite passive microwave sensors in the GPM constellation are intercalibrated to the GPM Combined Instrument product (because it is presumed to be the best snapshot GPM estimate), then "morphed" and combined with microwave precipitation-calibrated geo-IR fields, and adjusted with monthly surface precipitation gauge analysis data (where available) to provide half-hourly and monthly precipitation estimates on a 10-km grid over the domain 60 degrees N-S. Precipitation phase is diagnosed using analyses of surface temperature, humidity, and pressure. The "Final" multi-satellite product is derived from the half-hourly GPM_3IMERGHH. The derived result represents the final estimate of the daily accumulated precipitation. It available as a daily composite in Worldview and the Global Imagery Browse Services (GIBS). The imagery resolution is 2 km, and the temporal resolution is daily.
References: GPM_3IMERGDF: GPM IMERG Final Precipitation L3 1 day 0.1 degree x 0.1 degree V06