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).
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, ftp://arthurhou.pps.eosdis.nasa.gov/gpmdata/
For more details on citation format, please refer to the American Meteorological Society Data Archiving and Citation guidelines: http://www2.ametsoc.org/ams/index.cfm/publications/authors/journal-and-bams-authors/journal-and-bams-authors-guide/data-archiving-and-citation/\
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 one of the following general data access page identifiers:
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 FTP (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."