TRMM Kwajalein Ground Validation Research

The Tropical Rainfall Measuring Mission (TRMM) is a joint mission between NASA and the National Space Development Agency (NASDA) of Japan to study tropical rainfall and the vertical gradient of heating caused by precipitating cloud systems. The TRMM satellite was launched November 27, 1998 and contains a unique combination of instrumentation, including the first quantitative spaceborne Precipitation Radar (PR), a multi-channel passive Microwave Radiometer (TMI), a Visible and Infrared Scanner (VIRS), a Cloud and Earth Radiant Energy System (CERES), and a Lightning Imaging Sensor (LIS).

The TRMM science program includes an extensive effort to validate the satellite measurements. Ten ground validation sites are located throughout the tropics. Each site consists of a calibrated radar and a network of rain gauges. Four of these sites are considered primary or "direct data" sites from which a continuous data stream of high quality is to be obtained through the life of the TRMM satellite. The direct data sites are Darwin, Australia; Melbourne, Florida; Kwajalein Atoll, Republic of the Marshall Islands; and Houston, Texas. Each of these four sites has a PI and institution responsible for monitoring the data stream from the site. The following information pertains to the Kwajalein Atoll Ground Validation site overseen by Professor Robert Houze at the University of Washington.