As of January 19, 2021, FTP access to the GPM research / production data server "arthurhou" is no longer available, and you must use either FTPS or HTTPS to access GPM research data. Click here to learn more.
IMERG Early Run Example January 24th, 2020

Data Usage Policy & Citation Instructions

GPM & TRMM Data Usage Policy

GPM and TRMM data are freely available at all levels for which the particular sensor or sensor combination has been processed by GPM. For the GPM Core Observatory this is for Levels 0 through 3 products (as applicable).  For the partner satellites in the GPM constellation this is Levels 1c through 3 (as applicable).

Users are encouraged to access data from the primary GPM and TRMM archives (i.e. domains at Goddard Space Flight Center). When data from secondary archives are used, it is incumbent on the user to verify that the data values accessed are accurate, up-to-date, current-version copies of the original data. Data format questions should be directed to the relevant archive site, while science questions should be sent to the dataset developers.

Finally, dataset users are asked to report errors and difficulties in the dataset to the dataset creators using the contact form below.

Point of Contact
Click here to submit a question through our contact form.


Data Citation Instructions

The data set source should be acknowledged when the data are used. One standard format for a formal reference is:

Dataset authors/producers, data release date: Dataset title, version. Data archive/distributor, access date in standard AMS format, data locator/identifier (doi or URL).

For example:

G. Huffman, D. Bolvin, D. Braithwaite, K. Hsu, R. Joyce, P. Xie, 2014: Integrated Multi-satellitE Retrievals for GPM (IMERG), version 4.4. NASA's Precipitation Processing Center, accessed 31 March, 2015,

For more details on citation format, please refer to the American Meteorological Society Data Archiving and Citation guidelines:\

View GPM & TRMM Data Product DOI's

View GPM Ground Validation DOI's


In the case of data sets that have not been given DOI’s, the most persistent "landing page" should be named as the "data locator", for example,

Note that the data locator is NOT the general data access page identifier: 

Rather it should be the DOI or landing page that gives the URL for the specific dataset accessed. 


When accessing data from the Precipitation Processing System servers (arhurhou and jsimpson), please reference the specific directory you retrieved the data from. Some directories require you to navigate by date, so in this case you can use placeholders.

For example, if you retrieved data from:

List the citation as:


As an “Acknowledgment”, one possible wording is:

"The <dataset name> data were provided by the NASA/Goddard Space Flight Center's <team's organization> and PPS, which develop and compute the <dataset name> as a contribution to <project (TRMM or GPM)>, and archived at the NASA GES DISC." 

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