Explanation of Data Products

Precipitation data sets, referred to as "products", are available at a variety of levels which denote the amount of processing that data has been through. These range from the raw instrument data to precipitation model outputs which are mathematically derived using the raw data as an input. Below are the definitions for each level:

Level 0 Raw instrument data
Level 1A Reconstructed, unprocessed instrument data at full resolution, time referenced, and annotated with ancillary information, including radiometric and geometric calibration coefficients and georeferencing parameters (i.e., platform ephemeris), computed and appended, but not applied, to Level 0 data.
Level 1B Radiometrically corrected and geolocated Level 1A data that have been processed to sensor units.
Level 2 Derived geophysical parameters at the same resolution and location as those of the Level 1 data.
Level 3 Geophysical parameters that have been spatially and/or temporally resampled from Level 1 or Level 2 data.
Level 4 Outputs or results from models using lower level data as inputs and, thus, not directly derived from the instruments.

At present, TRMM has each of these data products available for public download, except for the Level 4 products. Once the GPM Core Observatory is launched, these products will contain data processed from the GPM Core Observatory as well as the TRMM satellite. The products currently available from TRMM are listed below, as both instrument and gridded products. Information on each of these products is available here.

Product ID Product Name
Orbital Products
1B01 Visible and Infrared Radiance
1B11 Microwave Brightness Temperature (TMI)
1B21 Precipitaion Radar (PR) Power
1C21 Precipitation Radar (PR) Reflectivity
2A12 TMI Hydrometeor Profile
2A21 Precipitation Radar (PR) Surface Cross-Section
2A23 Precipitation Radar (PR) Rain Characteristics
2A25 Precipitation Radar (PR) Rainfall Rate and Profile
2B31 Combined Rainfall Profile (PR, TMI)
Gridded Products
3A11 Monthly 5° x 5° Oceanic Rainfall
3A12 Monthly 0.5° x 0.5° mean 2A12, profile, and surface rainfall
3A25 Monthly 5° x 5° and .5° x .5° Spaceborne Radar Rainfall
3A26 Monthly 5° x 5° Surface Rain Total
3B31 Monthly 5° x 5° Combined Rainfall
3A46 Monthly 1° x 1° SSM/I Rain
3B42 3-hour 0.25° x 0.25° TRMM and Other-GPI Calibration Rainfall
3B43 Monthly 0.25° x 0.25° TRMM and Other Sources Rainfall
CSH Monthly 0.5° x 0.5° Convective & Stratiform Heating