2B Combined

Single-orbit rainfall estimates from combined radar/radiometer data (GPM GMI & DPR, TRMM TMI & PR)

The GPM 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 GPM constellation. 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.

Processing Level
Current Algorithm Version
Dates Covered
December 1997 - April 2015 (TRMM), March 2014 - Present (GPM)
Minimum Latency
3 Hours (near real-time); 40 hours (research)
Spatial Resolution
Horizontal resolution: 5x5 km. Vertical resolution: 125m (DPR) and 250m (PR)
2B CMB PPS Near Real-time JacobAdmin Wed, 04/24/2019
Date Last Updated
December 17th, 2021
Document Description

This document describes the basic idea of DPR data processing. It was originally written for the algorithm used in the at-launch version (V03). The algorithm has been modified and improved since then. Although the basic idea of data processing remains the same, the actual flow of processing, in particular that in the solver module, has changed substantially. As a result, some part of description in Section 3.1 may not be relevant any more.

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