Satellite precipitation retrieval

Satellite precipitation retrieval is an analysis methodology: it does not rest on one sensor principle. IMERG-class products merge precipitation estimates from a constellation of passive-microwave sensors with microwave-calibrated geostationary infrared estimates, interpolation, and gauge adjustment to produce half-hourly global rainfall fields.^[1][2] It is useful for rainfall exposure and vector-borne-disease risk modelling, but it remains indirect for disease outcomes and is weakest for shallow, orographic, frozen, and rapidly evolving precipitation where sensor sampling or retrieval physics under-resolve the event.