Tropical Rainfall Measuring Mission

TRMM
Type:	Earth observation satellite
Country:	United States / Japan
Operator:	NASA / JAXA
COSPAR-ID :	1997-074A
Mission dates
Dimensions:	2391 kg
Begin:	November 27, 1997, 21:27 UTC
Starting place:	Tanegashima Y1
Launcher:	H-II F6
Flight duration:	17 years
Status:	burned up on June 15, 2015
Orbit data
Rotation time :	92 min
Orbit inclination :	35 °
Apogee height :	381 km
Perigee height :	366 km

The Tropical Rainfall Measuring Mission ( TRMM ) was a joint mission between NASA and the Japanese space agency JAXA with the aim of monitoring and studying rainfall in the tropics . TRMM was part of the Earth Observing System , a long-term research program by NASA. The satellite was launched on November 27, 1997 from the Tanegashima Space Center in Tanegashima , Japan and burned up over the Indian Ocean on June 15, 2015 at 03:55 UTC . TRMM was only designed for a service life of three years, but worked for over 17 years until April 15, 2015. The research is being continued with the successor satellite, Global Precipitation Measurement .

Instruments on board TRMM

Precipitation Radar (PR)

The Precipitation Radar ( English for precipitation radar ) was the first instrument on an earth satellite, which was capable of three-dimensional maps of storm structures create. The measurements contained information about the intensity, distribution and type of rain , the depth of the storm and the height at which the snow turns into rain. The estimates of the temperature at different heights of the atmosphere based on these measured values were useful, for example, in creating more accurate models of global atmospheric circulation.

TRMM Microwave Imager (TMI)

The TRMM Microwave Imager was a passive microwave sensor whose job it was to record large amounts of information about precipitation over a large area under the satellite. For this purpose, the amount of microwaves emitted by the earth and its atmosphere every minute was recorded. This enabled the instrument to determine both the amount of water vapor and water in the clouds and the intensity of the precipitation. The TRMM Microwave Imager was a comparatively small instrument and also managed with little energy. Given the wealth of information this instrument provided about precipitation, it was one of the most important instruments on board the satellite.

Visible and Infrared Scanners (VIRS)

The Visible and Infrared Scanner (English for scanner for visible light and infrared radiation ) was one of the three instruments whose task it was to measure precipitation. The instrument perceived the precipitation in a very indirect way. VIRS recorded the radiation emitted by the earth in five different spectra , ranging from visible light to infrared radiation (0.63 to 12 micrometers ). With the intensity of the radiation in the different spectra, the brightness (visible light and near infrared) or the temperature (infrared) of the source could be determined.

Clouds and the Earth's Radiant Energy System (CERES)

The instrument CERES (English for Radiation Energy System of Clouds and Earth ) measured the energy in the uppermost regions of the atmosphere and also estimated the energy levels within the atmosphere and on the earth's surface. With the help of the other instruments on board the satellite, CERES also determined the cloud properties , including the degree of cloud cover , the altitude, the density and the size of the cloud particles. All of these measured values ​​were decisive for understanding the entire climate system of the earth and also improved the models for climate prediction .

Lightning Imaging Sensor (LIS)

The Lightning Imaging Sensor (English for sensor for imaging flashes ) was a small instrument that lightning over the tropical regions could identify and locate. The device was a combination of optical and electrical elements. The sensor's field of view made it possible to observe a point on the earth or a cloud for 80 seconds, which was enough to estimate the number of lightning strikes. These values ​​indicated to the researchers whether the storm was still growing or was already subsiding.

Web links

• Official Homepage of the project (English)

Individual evidence

1. ↑ ^{a b} Chris Bergin: TRMM spacecraft completes destructive re-entry over South Indian Ocean. nasaspaceflight.com, June 15, 2015, accessed June 17, 2015 . 
2. ↑ TRMM - orbit data in the NSSDCA Master Catalog , accessed on October 11, 2012 (English).