Integrated Multi-satellite Retrievals for the Global Precipitation Measurement (GPM) Mission (IMERG)

The Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM) mission (IMERG) is a US GPM Science Team precipitation product. IMERG uses inter-calibrated estimates from the international constellation of precipitation-relevant satellites and other data, including monthly surface precipitation gauge analyses, to compute half hour, 0.1° × 0.1° gridded datasets over 60°N-S (and partially outside of that latitude band) in three “Runs”—Early (4 h after obs time), Late (14 h after obs time), and Final (3.5 months after obs time). The concepts behind IMERG are briefly reviewed, together with major shifts related to changes in versions from the at-launch Version 03 to Version 05, and an outline of Version 06, which was released in late 2019.