# Satellite precipitation retrieval
*analysis . methodologies*

Integrates passive-microwave precipitation estimates with microwave-calibrated infrared observations and interpolation to produce near-global rainfall fields, exemplified by GPM IMERG.

## Specifications
- **family**: Fusion
- **requirements envelope**: {"kind":"fusion","component_methodology_atlas_ids":["2cabd9cb-027f-463f-bc62-319a8d3a485b"],"integration_pattern":"intercalibrate passive-microwave estimates, propagate them in time, merge microwave-calibrated infrared estimates, and apply gauge correction where available","cadence_max_days":1,"gsd_max":10000}
- **entity type**: methodology
- **last verified date**: 2026-06-08
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **subtype**: analysis
- **attributes**: {"family":"Fusion","kind":"analysis","summary":"Integrates passive-microwave precipitation estimates with microwave-calibrated infrared observations and interpolation to produce near-global rainfall fields, exemplified by GPM IMERG.","requirements_envelope":"{\"kind\":\"fusion\",\"component_methodology_atlas_ids\":[\"2cabd9cb-027f-463f-bc62-319a8d3a485b\"],\"integration_pattern\":\"intercalibrate passive-microwave estimates, propagate them in time, merge microwave-calibrated infrared estimates, and apply gauge correction where available\",\"cadence_max_days\":1,\"gsd_max\":10000}"}
- **relevance**: in-scope

## Editorial
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.[^nasa-gpm-imerg][^imerg-atbd] 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.

## Sources
- [nasa-gpm-imerg] | IMERG: Integrated Multi-satellitE Retrievals for GPM | https://gpm.nasa.gov/data/imerg | tier=agency-doc | accessed=2026-06-08 | author=NASA Global Precipitation Measurement Mission
- [imerg-atbd] | Integrated Multi-satellitE Retrievals for GPM (IMERG) Algorithm Theoretical Basis Document | https://gpm.nasa.gov/resources/documents/algorithm-information/IMERG-V06-ATBD | tier=agency-doc | accessed=2026-06-08 | author=NASA Global Precipitation Measurement Mission

---
Source: https://eo-atlas.org/methodologies/satellite-precipitation-retrieval
Maintainer: SpectraWorks B.V. (CC-BY 4.0)