This a new (GPM-formated) TRMM product, for the TRMM epoch (December 1997 - April 2015), created using GPM Algorithms. There is no equivalent in the old TRMM suite of products.

This is the GPM-like formatted TRMM Combined Precipitation (TRMM Ku radar and microwave radiometer/imager), first released with the "V8" TRMM reprocessing.

Combined Radar-Radiometer Algorithm performs two basic functions:

First, it provides, in principle, the most accurate, high resolution estimates of surface rainfall rate and precipitation vertical distributions that can be achieved from a spaceborne platform, and it is therefore valuable for applications where information regarding instantaneous storm structure are vital.

Second, a global, representative collection of combined algorithm estimates will yield a single common reference dataset that can be used to “cross-calibrate” rain rate estimates from all of the passive microwave radiometers in the TRMM and GPM constellations.

The cross-calibration of radiometer estimates is crucial for developing a consistent, high time-resolution precipitation record for climate science and prediction model validation
applications.