IMERG Early Run Example January 24th, 2020

Data

Precipitation data from the GPM and TRMM missions are made available free to the public in a variety of formats from several sources at NASA Goddard Space Flight Center. This section outlines the different types of data available, the levels of processing, the sources to download the data, and some helpful tips for utilizing precipitation data in your research.

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Frequently Asked Questions

How do I get precipitation data for my specific location?

There are several sources for downloading and viewing data which allow you to subset the data to only include specific parameters and/or geographic locations. These include the GES DISCGiovanni and STORM. In Giovanni you can obtain data for a specific country, U.S. state, or watershed by using the "Show Shapes" option in the "Select Region" pane.

What happened to the TRMM Multi-satellite Precipitation Analysis (TMPA / 3B4x) data products?

The TRMM satellilte has been decommissioned and stopped collecting data in April 2015. The transition from the Tropical Rainfall Measuring Mission (TRMM) data products to the Global Precipitation Measurement (GPM) mission products has completed as of August 2019. The GPM IMERG dataset now includes TRMM-era data from June 2000 to the present, and other TRMM-era data has been reprocessed with GPM-era algorithms and is now available on the GPM FTP servers. TMPA data production ended as of December 31st, 2019 and the TRMMOpen FTP server has been shut down. Historical TMPA data is still available to download from the NASA GES DISC at: https://disc.gsfc.nasa.gov/datasets?keywords=TMPA&page=1

Click here for more details on the transition from TMPA to IMERG. 

Am I allowed to use GPM data for my research?

Yes, in line with NASA's general data policy. Please refer to the GPM Data Policy for further details.

How do I give credit for using GPM data?
Where can I find detailed documentation on the precipitation algorithms?

Browse our directory of GPM & TRMM data products to locate your desired algorithm, then click on the links in the algorithm description under "Documentation". All documentation is also available at the Precipitation Processing System website

What is the spatial and temporal resolution of GPM data?

The resolution of Level 0, 1, and 2 data is determined by the footprint size and observation interval of the sensors involved.  Level 3 products are given a grid spacing that is driven by the typical footprint size of the input data sets.

For our popular multi-satellite GPM IMERG data products, the spatial resolution is 0.1° x 0.1° (or roughly 10km x 10km) with a 30 minute temporal resolution.

Visit the directory of GPM & TRMM data products for details on the resolution of each specific products.

Can I use images or videos from this site or other NASA websites?

For questions about permission for using NASA images and videos, please refer to NASA's official Media Usage Guidelines. For any additional questions please contact bert.ulrich@nasa.gov

Is it possible to subset GPM data?

There are several sources for downloading and viewing data which allow you to subset the data to only include specific parameters and/or geographic locations. These include the GES DISCGiovanni and STORM. In Giovanni you can obtain data for a specific country, U.S. state, or watershed by using the "Show Shapes" option in the "Select Region" pane.

What is the difference between "Near Real-time" (NRT) and "Production" / "Research" data?

GPM data products can be divided into two groups (near real-time and production) depending on how soon they are created after the satellite collects the observations. For applications such as weather, flood, and crop forecasting that need precipitation estimates as soon as possible, near real-time data products are most appropriate.  GPM near real-time (GMI & DPR) products are generally available within a few hours of observation.  For all other applications, production data products are generally the best data sets to use because additional or improved inputs are used to increase accuracy.  These other inputs are only made available several days, or in some cases, several months, after the satellite observations are taken, and the production data sets are computed after all data have arrived, making possible a more careful analysis.

For the GPM IMERG dataset, IMERG Early and Late Runs are the near real-time products, while IMERG Final Run is the research / production product. Click here to learn more about the differences between IMERG Early, Late and Final. 

The following is a clarification on the current status of Version 06 and Version 07 IMERG data. Production of V06 Early and Late datasets ceased on 3 June. After overcoming significant hardware, software, and data feed challenges, PPS instituted “Initial Processing” (that is, processing of new data) for Early and Late starting with 00:00 UTC on 1 June. “Retrospective Processing” (that is, processing of the record of previous data) is complete for Early from June 2000 through December 2023. Retrospective Processing is on-going for Late, with parallel runs starting with June 2000 and June 2014...
At 01:45 UTC 12 June, JAXA resumed their processing of GPM radar products, which allowed PPS to catch up the downstream GPM DPR products that they compute, as well as computing the Combined product. Fortunately, through the processing outage the JAXA-NASA data line continued to operate, providing the ancillary data that GPROF and IMERG needed to continue uninterrupted near real-time processing.
The PPS is now receiving AMSR2 data and JMA forecasts from JAXA, which means that GPROF and IMERG Early and Late products will continue being produced. The GPM radar and combined products are still unavailable due to the JAXA system issues. The PPS has also worked with partners at CSU to develop a new method of processing GPROF that will allow continued production even if no JMA forecast files are received, in the event of a future outage.
Due to an unexpected JAXA system failure the PPS is not receiving GPM DPR Ku and Ka L1B data as well as AMSR2 data. As a result, the PPS cannot produce the GPM radar or combined datasets. The PPS is also not receiving JMA 6 hourly forecasts, and as a result after 12:00 UTC on June 11, 2024 the PPS will not be able to produce the GPROF or IMERG products. JAXA estimates that their systems will start running again by 03:00 UTC 12 June, at which point production of the above products at the PPS will resume. Please check back here for further updates, and contact us with any questions.
The new V07B IMERG Late and Early Run products commenced processing around 1300 UTC on 6 June 2024, starting with data for 0000 UTC on 1 June 2024. It will take a number of hours for the days before 6 June to be processed, after which users should see the normal latencies of 4 and 12 hours for Early and Late, respectively. Note that the polar regions are initially largely set to "missing" in the Early Run because input data for times before 1 June that would normally be used for forward morphing are not provided as part of the startup.

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