At NASA's Goddard Space Flight Center in Greenbelt, Maryland, an analysis of Hurricane Harvey's tremendous rainfall was created using eight days of satellite data.NASA's Integrated Multi-satellitE Retrievals for GPM or IMERG product is used to make estimates of precipitation from a combination of space-borne passive microwave sensors, including the GMI microwave sensor onboard the Global Precipitation Measurement satellite GPM core satellite, and geostationary IR (infrared) data.