Browse our directory of GPM data products (https://gpm.nasa.gov/data/directory) 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 (https://pps.gsfc.nasa.gov/). Note that "GPM data products" includes data from both the GPM and TRMM eras, uniformly processed using the most current GPM-based algorithms.

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:

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

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.

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 DISC, Giovanni 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.