IMERG Late Run

Near real-time gridded global multi-satellite precipitation estimates with quasi-Lagrangian time interpolation
Description

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 (IMERG Early Run) and successively providing better estimates as more data arrive (IMERG Late Run). The final step uses monthly gauge data to create research-level products (IMERG Final Run). 

The main difference between the IMERG Early and Late Run is that Early only has forward propagation (which basically amounts to extrapolation), while the Late has both forward and backward propagation (allowing interpolation). The additional 10 hours of latency allows lagging data transmissions to make it into the Late run, even if they were not available for the Early. 

Notes:

  • The PPS has completed reprocessing GPM IMERG data for IMERG V06B. The IMERG dataset now includes TRMM-era data going back to June 2000.
  • As of IMERG V05B, full coverage is provided for the latitudes of 60°N-60°S, while the remaining upper and lower latitudes extending to 90° are considered "partial coverage". 
Processing Level
3
Current Algorithm Version
V07B
Dates Covered
June 2000 - Present
Minimum Latency
12 Hours
Spatial Resolution
10km / 0.1 Degree
Date Last Updated
July 13th, 2023
Document Description

The Integrated Multi-satelliE Retrievals for GPM (*IMERG*) is the unified U.S. algorithm that provides the multi-satellite precipitation product for the U.S. GPM team.

Date Last Updated
July 11th, 2023
Document Description

(document coming soon)

Date Last Updated
July 12th, 2023
Document Description

This document describes the algorithm and processing sequence for the Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM) mission (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 Tropical Rainfall Measuring Mission (TRMM) and GPM eras over the entire globe.

Date Last Updated
February 21st, 2024
Document Description

The algorithm for the Integrated Multi-satellitE Retrievals for GPM (IMERG) has now been upgraded to Version 07.  IMERG V07 involves a wide range of changes to all aspects of the algorithm, many of which are implemented in response to feedback on V06, which was the first time the IMERG record spanned the TRMM-GPM eras.  IMERG V07 is being reprocessed for the entire TRMM-GPM record and thus supersedes all prior IMERG versions, as well as superseding the prior TRMM-based TMPA products (3B42, 3B43).

Date Last Updated
June 27th, 2023
Document Description

NASA produces a GIS translation of IMERG for various accumulation periods. The GIS translation maintains the 0.1-degree spatial resolution of the original HDF5 data product. In July 2023, Version 7 IMERG was released in both HDF5 and GIS formats. In April 2019, Version 6 of IMERG had been released, covering June 2000 to 2019. The long- duration archive for all versions starting with Version 6 is a boon to scientific research and provides a training set for near real-time applications such as disaster monitoring.

IMERG Late Run PPS Near Real-time HDF JacobAdmin Wed, 04/24/2019
IMERG Late Run GES DISC JacobAdmin Wed, 04/24/2019