1. TRMM/TMI Michael Blecha EECS 823

2.  TMI : TRMM Microwave Imager  PR: Precipitation Radar  VIRS: Visible and Infrared Sensor  CERES: Cloud and Earth Radiant Energy Sensor  LIR: Lighting Imaging Sensor TRMM Instruments

3. ChannelFrequencyPolarization 110.65 GHzVertical 210.65 GHzHorizontal 319.35 GHzVertical 419.35 GHzHorizontal 521.3 GHzVertical 637.0 GHzVertical 737.0 GHzHorizontal 885.5 GHzVertical 985.5 GHzHorizontal TRMM/TMI Channels

4.  Orbit height of 402km  Oriented 49 o relative to nadir  Beam width and effective area different per frequency  Dual calibration: on board “hot load” and space as cold load TRMM/TMI Orientation Figure 1: TRMM (Kummerow et al )

5.  36.1 scans per minute  16 orbits per day  Semi-equatorial orbit (35 o incline with respect to the equator) TRMM/TMI Orbit Figure 2: Daily orbit (NASA)

6. TRMM/TMI Data Products TMI 1A: Raw TMI Signal PR 1A: Raw PR Signal 1B11: Calibrated Antenna Temperature 1B21: PR Power 2A12: Rainfall Structure 2A23: Rainfall Occurrences 3A11: Combined Monthly Rainfall 2B31: Combined Rainfall Structure 1C12: PR Reflectivity

7.  Currently on version 7 of algorithm  Conversion of brightness temperature to rainfall rate  Goddard Profiling Algorithm (GPROF)  Land algorithm separate from ocean algorithm  Land algorithm less accurate because it relies primarily on scattering from the 85G channels  Ocean algorithm uses weighting of scattering and emissive upwelling radiation  Extensive use of cloud models to predict rainfall based on cloud characteristics 1B11 -> 2A12

8.  Fu, Yunfei, et al. "A feasible method for merging the TRMM microwave imager and precipitation radar data." Journal of Quantitative Spectroscopy and Radiative Transfer (2013): 155-169.  GES DISC. TRMM Microwave Imager (TMI) LEVEL 1B Calibrated Brightness Temperature (TB) Product. n.d. 5 December 2014.  Goddard Space Flight Center. NASA Facts: TRMM Instruments. n.d. 5 December 2014.  Kummerow, Christian, et al. "The Evolution of the Goddard Profiling Algorithm (GPROF) for Rainfall Estimation from Passive Microwave Sensors." Journal of Atmospheric and Oceanic Technology (2001): 1801-1820.  Kummerow, Christian, William Barnes and Toshiaki Kozu. "The Tropical Rainfall Measuring Mission (TRMM) Sensor Package." Journal of Atmospheric and Oceanic Technology (1998): 809-817.  Wang, Nai-Yu, et al. "TRMM 2A12 Land Precipitation Product – Status and Future Plans." Journal of the Meteorological Society of Japan (2009): 237-253. References