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.
The Level 3 DPR product provides space-time statistics of the level 2 DPR results. High and low spatial resolution grids are defined such that the high-resolution grid is 0.250 × 0.250 (lat×lon) while the lowresolution grid is 50 ×50. For the variables defined on the low-resolution grid, the statistics include mean, standard deviation, counts and histogram. For variables defined on the high-resolution grid, the same
statistics are computed with the exception of a histogram, which is omitted.
Not all raindrops are created equal. The size of falling raindrops depends on several factors, including where the cloud producing the drops is located on the globe and where the drops originate in the cloud. For the first time, scientists have three-dimensional snapshots of raindrops and snowflakes around the world from space, thanks to the joint NASA and Japan Aerospace Exploration Agency Global Precipitation Measurement (GPM) mission.
Late on March 2, 2016, the GPM NRT system will begin using V04 algorithms for:
- Level 1B GMI
- Level 1C GMI
- Level 1 Radar
- Level 2 Radar
- Level 2 Combined
V04 is the first version that uses GPM as the calibrator for the constellation rather than TRMM. The GPROF database is built using the combined observations. GMI is extremely well calibrated and the brightness temperatures in 1B and 1C are an important improvement over those in V03.
Cyclone Joalane had developed a small clear eye when the GPM core observatory satellite passed above on April 7, 2015 at 1436 UTC. GPM's Microwave Imager (GMI) data showed that the heaviest rain was falling at a rate of over 78.6 mm (3 inches) per hour in a feeder band wrapping around Joalane's eastern side.
PPS is re-releasing the first public version IMERG products The Integrated Multi-satellitE Retrievals for GPM (IMERG) merges precipitation estimates from passive microwave sensors, geo-IR, and monthly surface precipitation gauge analysis data (where available) to provide half-hourly and monthly precipitation estimates and related fields on a 0.1° lat./long. grid over the domain 60°N-S.