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.

Beginner Resources

Training

Tutorials

Data Visualization

Data FAQ

Learn about IMERG

 

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. 

Starting at 16:33 UTC July 6 a filled log directory led to sh commands failing on redirecting logs to be created in that directory. A typo in the cleanup routine failed to clean our all the files after the normal 4 days. As a result they have been accumulating since the beginning of the mission. It is unexpected that the sh failed when it could not redirect anymore. All data products that failed have been created and put in the appropriate directories. However, this will mean a failure in the data latency requirements for some of the GMI L1B and GPROF and a few combined products.
Starting at 08:38 UTC PPS stopped getting data from the GPM Mission Operations Center. Data was resumed at 17:21 UTC. However, new GPS data was sent before older GPS data. The science data was sent out of order with the GPS data. This meant that about 125 mins of 1B and 1C GMI data had no geolocation and perhaps more after this had questionable geolocation. The same issues obviously also affected the radar and combined NRT which are just missing for the period between 8:30 UTC and 17:30 UTC. All of these issues impacted the early version of the IMERG data. The late product will also be...
NOAA has reprocessed the global IR data for 10 UTC 26 April through 14 UTC 27 April due to dropped images, and all 3B41RT and 3B42RT files for this time period have been reprocessed by PPS and are now available: 3B41RT.2015042610.7.bin.gz through 3B41RT.2015042714.7.bin.gz 3B42RT.2015042612.7.bin.gz through 3B42RT.2015042715.7.bin.gz Such partial dropouts in the IR data result in somewhat lower quality for IMERG Early and Late Runs, but are not cause for reprocessing.
On Sunday, April 26, 2015, between the hours of 12 noon (17 UTC) and 12 midnight EDT (05 UTC April 27) , changes will be implemented to NASA’s Internet access. The purpose of this outage is to complete the Corporate Route Symmetry Project which is being implemented by the Communications Services Office (CSO). As a result of these changes, users can expect an outage to the below services during this time period. Services Affected: On Sunday, April 26, 2015, changes to NASA’s Internet Access will have the following impacts: Internet access to/from all NASA networks External Virtual Private...
The issues with NOAA's 4-km Merged IR data are closed and the IMERG Early and Late Runs have been restarted from the point at which they stopped. This will provide a continuous record for each, but it also means that it will take a while to process the backlog of data and catch up to the nominal latency.

Hide Body

Hide Date