Precipitation Processing System

The L3GPROF algorithm provides monthly and daily mean precipitation and related retrieved parameters from the Level 2 GPROF precipitation profiling algorithm for the GPM core and constellation satellites.

Each L3GPROF product contains global 0.25o x 0.25o gridded monthly/daily unconditional means and pixel counts. Monthly product filenames start with 3A-MO or 3A-CLIM-MO, and daily product filenames start with 3A-DAY or 3A-CLIM-DAY.

This Level 3 GPROF Version 07 release involves the following changes from the previous
(Version 05) release:

1. Product format change:
Added dimension variables such as lat, lon, layer, lat_bnds, lon_bnds, layer_bnds. Removed
cloudIce variable but added graupel and latentHeating variables.
2. Total number of precipitation pixels (npixPrecipitation):
In Version 05, pixels with pixelStatus=0 and surfacePrecipitation > 0 are counted as
precipitation pixels. In Version 07, pixels with pixelStatus=0, surfacePrecipitation > 0 and

1AGMI contains unpacked packet data from GMI science data from the GMI passive
microwave instrument flown on the GPM satellite. Swath S1 has 9 channels which are
similar to TRMM TMI (10V 10H 19V 19H 23V 37V 37H 89V 89H). Swath S2 has 4
channels similar to AMSU-B (166V 166H 183+/-3V 183+/-8V). Data for both swaths
is observed in the same revolution of the instrument. Swath S3 has ScienceDataHeader.
Swath S4 has full rotation for low freq channels (S1). Swath S5 has full rotation for high
freq channels (S2).

The Level-3 radar products provide daily and monthly global statistics of the Level-2 Ku, Ka and DPR products on a latitude-longitude grid. In version 7 (V07), the organization of the products has changed with the highest-level categorization into FS (full swath), MS (matched or inner swath) and HS (high sensitivity) swath products. The next level of division is into high and low spatial resolution grids that are defined such that the low-resolution grid (G1) is 50×50 (lat×lon) while the high-resolution grid (G2) is 0.250× 0.250.

Level 1C (L1C) algorithms are a collection of algorithms that produce common calibrated brightness temperature products for the Global Precipitation Measurement (GPM) Core and Constellation satellites.

This document describes the GPM Level 1C algorithms. It consists of physical and mathematical bases for orbitization, satellite intercalibration, and quality control, as well as the software architecture and implementation for the Level 1C algorithms.