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TRMM Product List
TRMM Solar Array Anomaly
TRMM Satellite Altitude to be Raised to 400km
TRMM Orbit Information
Use the TRMM data

Please refer "Data Distribution Service" page for further information on TRMM.
  • TRMM products available list
  • Update of TRMM Data Users Handbook


Global environment change has become a worldwide concern. Satellite remote sensing is recognized as a powerful and essential means for monitoring global change. TRMM is the first space mission dedicated to quantitatively measuring tropical and subtropical rainfall which is one of the most important and least-known parameters affecting the global climate system.

TRMM is a joint project between Japan and the United States in 1986. JAXA (Old:NASDA) is responsible for developing a key instrument, the Precipitation Radar (PR), in collaboration with NICT(Old:CRL) of Ministry of Public Management, Home Affairs, Posts and Telecommunications. JAXA(Old:NASDA) will also provide the launch of the TRMM satellite by H-II rocket.

The U.S. National Aeronautics and Space Administration (NASA) is responsible for the development of the spacecraft and four instruments including the TRMM Microwave Imager (TMI), the Visible Infrared Scanner (VIRS), the Clouds and Earth's Radiant Energy System (CERES), and the Lightning Imaging Sensor (LIS), and satellite operations using the Tracking and Data Relay Satellite (TDRS) System.


To better understand global changes (e.g.,"EI Nino" and desertification of land) and their mechanisms, scientists require long-term observations of the Earth System and the interactions of the atmosphere, oceans, and lands. In particular, the hydrological cycle and energy budget are among the most important issues to be studied to understand the global climate system.

More than two-thirds of global precipitation falls in tropics and subtropics. The latent heat released by this rainfall plays a vital role in the global atmospheric circulation and the energy budget. The major objective of TRMM is to increase our understanding of global climate change through space-based measurements of tropical rainfall and Earth radiation. TRMM is a key element of "Mission to Planet Earth," an international science program to provide the measurements necessary to understand our Planet as a system.

The rain radar, with its first space-based flight on TRMM, will be a prototype for future spaceborne microwave remote sensors. The non-sunsynchronous TRMM orbit will provide observations of the diurnal cycle of rainfall, which are not possible from existing sun-synchronous satellites such as MOS-1 and JERS-1. Results from TRMM will build the foundation for continuing programs for long-term observations of global rainfall and climate change.


In order to have effective measurement of the average precipitation over the tropical region, TRMM is planned to be launched in the orbit with various instruments as follows.

Launch Mass About 3.62t
Launch Vehicle H-II Rocket
Launch Date 28.November1997
Altitude About 350km
Inclination About 35deg.
Power About 850W(average)
Altitude Control 3 Axis Zero-momentum
Data Rate 32Kbps (Real Time) , 2Mbps (Play Back)
Mission Life 3 years
Instruments Precipitation Radar(PR)
Visible Infrared Scanner(VIRS)
TRMM Microwave Imager(TMI)
Clouds and the Earth's Radiant Energy System(CERES)
Lightning Imaging Sensor(LIS)
Data Transmission Via TDRS

Japan and the U.S. Responsibilities

The TRMM is a joint program between Japan and the United States. The primary elements of responsibility are listed below.

Japan U.S.
  • H-II Rocket
  • PR
    (Mission Instruments)
  • Data System
Mission Instruments
  • VIRS
  • TMI
  • LIS
    Tracking & S/C Operation
  • Data System

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