| Since the launch of the Tropical Rainfall Measuring Mission (TRMM) the Precipitation Measurement Missions science team has endeavored to provide TRMM precipitation retrievals in a variety of formats that are more easily usable to the broad science community than the standard Hierarchical Data Format (HDF) in which TRMM data is produced and archived. At the request of users, the Precipitation Processing System (PPS) has developed a .25 x .25 gridded product in an easily used ASCII text format. The entire TRMM mission data has been made available in this format.
This paper provides the details of this new precipitation product that is designated with the TRMM designator 3G68.25. The format is packaged into daily files. It provides hourly precipitation information from the TRMM microwave imager (TMI), precipitation radar (PR), and TMI/PR combined rain retrievals. A major advantage of this approach is the inclusion only of rain data, compression when a particular grid has no rain from the PR or combined, and it direct ASCII text format. For those interested only in rain retrievals and whether rain is convection or stratiform these products provide a huge reduction in the data volume inherent in the standard TRMM products.
This paper provides examples of the 3G68 data products and their uses. It also provides information about java tools that can be used to aggregate the daily file into larger time samples. In addition, it describes the possibilities inherent in the spatial sampling which allows resampling into coarser spatial sampling.
The paper concludes by providing information about retrieving these data products. |