George J. Huffman

Date Last Updated
April 26th, 2019
Document Description

This document describes the algorithm and processing sequence for the Integrated Multi-satellitE Retrievals for GPM (IMERG).  This algorithm is intended to intercalibrate, merge, and interpolate “all” satellite microwave precipitation estimates, together with microwave-calibrated infrared (IR) satellite estimates, precipitation gauge analyses, and potentially other precipitation estimators at fine time and space scales for the TRMM and GPM eras over the entire globe.

Date Last Updated
March 11th, 2019
Document Description

In IMERG up through V05, the cloud motion vector computation approach used is that pioneered in CMORPH (Joyce et al. 2011), in which motion vectors are computed from 4-km geosynchronous infrared (GEO-IR) brightness temperatures. Hence, the motion vectors reflect cloud top motions. However, there are two main limitations in using GEO-IR. The first limitation is that cloud top motions may not match precipitation motions due to both wind shear and the growth and decay of precipitation systems.

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Document Description

A table comparing the older TRMM Multi-satellite Preciptiation Analysis (TMPA) datasets with the new Integrated Multi-satellitE Retrievals for GPM (IMERG) datasets. 

Date Last Updated
November 1st, 2019
Document Description

The transition from the Tropical Rainfall Measuring Mission (TRMM) data products to the Global Precipitation Measurement (GPM) mission products has begun. This document specifically addresses the multi-satellite products, the TRMM Multi-satellite Precipitation Analysis (TMPA), the real-time TMPA (TMPA-RT), and the Integrated Multi-satellitE Retrievals for GPM (IMERG).

Document Description

This document describes the algorithm and processing sequence for the Integrated Multi-satellitE Retrievals for GPM (IMERG).  This algorithm is intended to intercalibrate, merge, and interpolate “all” satellite microwave precipitation estimates, together with microwave-calibrated infrared (IR) satellite estimates, precipitation gauge analyses, and potentially other precipitation estimators at fine time and space scales for the TRMM and GPM eras over the entire globe.  The system is run several times for each observation time, first giving a quick estimate and successively providin

Document Description
Motivated by the recent increasing availability of global remote sensing data for estimating precipitation and describing land surface characteristics, this note reports an approximate assessment of quasi-global runoff computed by incorporating satellite rainfall data and other remote sensing products in a relatively simple rainfall-runoff simulation approach: the Natural Resources Conservation Service (NRCS) runoff curve number (CN) method.