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Active and Passive Remote Sensing Diagram

Diagram illustrating the differences between active and passive remote sensing.
Image Caption
This diagram illustrates the differences between active and passive remote sensing.

TRMM and GPM rely on active and passive instruments to measure the properties of precipitation from space.

Active radars, such as the TRMM Precipitation Radar, transmit and receive signals reflected back to the radar. The signal returned to the radar receiver (called radar reflectivity) provides a measure of the size and number of rain/snow drops at multiple vertical layers in the cloud (Left figure).

TRMM Monitors Southern Mexico's Rainfall

TRMM image of rainfall in Southern Mexico
The TRMM satellite flew over an area of disturbed weather labeled 95L affecting southern Mexico on 27 June 2011 at 2148 UTC (5:48 PM EDT). The TRMM rainfall analysis shown above used TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data. It shows that heavy rainfall of over 50mm (~2 inches) associated with 95L was occurring in southern Mexico northwest of Veracruz and over the Yucatan Peninsula. Some of this very heavy rainfall may result in flash flooding and mudslides. The National Hurricane Center (NHC) is watching this area and has indicated that there is a slight chance that a

Successful Completion of KDP-C Review

GPM has successfully completed the GPM Mission Key Decision Point - C (KDP-C) Review on December 2, 2009, which formally confirms the Implementation phase of the GPM Mission. Key Decision Point C (KDP-C) is the agency-level approval for the project to begin implementation, and baselines the project’s official schedule and budget. The review process for KDP-C starts with the Preliminary Design Review/Non-Advocate Review (PDR/NAR) to the project’s Standing Review Board (SRB). Next, the project and SRB report to the GSFC Center Management Council at the Confirmation Readiness Review (CRR). Based

GPM Integrated Multi-Satellite Retrievals for GPM (IMERG) Algorithm Theoretical Basis Document (ATBD) v5.2

Document Description

This document describes the algorithm and processing sequence for the Integrated Multi-satellitE Retrievals for GPM (IMERG).  This algorithm is intended to intercalibrate, merge, and interpolate “all” satellite microwave precipitation estimates, together with microwave-calibrated infrared (IR) satellite estimates, precipitation gauge analyses, and potentially other precipitation estimators at fine time and space scales for the TRMM and GPM eras over the entire globe.  The system is run several times for each observation time, first giving a quick estimate and successively providin

GPM GPROF Algorithm Theoretical Basis Document (ATBD)

Date Last Updated
May 15th, 2022
Document Description

This ATBD describes the Global Precipitation Measurement (GPM) passive microwave rainfall algorithm, which is a parametric algorithm used to serve all GPM constellation radiometers. The output parameters of the algorithm are enumerated in Table 1. It is based upon the concept that the GPM core satellite, with its Dual Frequency Radar (DPR) and GPM Microwave Imager (GMI), will be used to build a consistent a-priori database of cloud and precipitation profiles to help constrain possible solutions from the constellation radiometers.

File Downloads
ATBD_GPM_V7_GPROF.pdf
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