TRMM
Combination
The Tropical
Rainfall Measurement Mission (TRMM) is being flown by the National
Aeronautics and Space Administration (NASA, U.S.) and the National Aeronautics
and Japan Aerospace Exploration Agency (JAXA, Japan) to improve our
quantitative knowledge of the 3-dimensional distribution of precipitation in the
tropics. TRMM has a passive microwave radiometer (TRMM Microwave Imager, TMI),
the first active space-borne Precipitation Radar (PR), and a Visible-Infrared
Scanner (VIRS), plus other instruments. Coordinated observations are intended
to result in a "flying raingauge" capability.
Two of the products produced operationally in
TRMM are the "TRMM and Other Satellites" precipitation estimate
(Algorithm 3B-42) and the "TRMM and Other Sources" precipitation
estimate (Algorithm 3B-43) described in Huffman et al. (2007). Algorithm 3B-42
uses the TRMM Multi-satellite Precipitation Analysis (TMPA) algorithm to
calibrate the TMI (2A-12), SSM/I, AMSR-E, AMSU-B and IR to the TRMM
best-estimate TCI (2B-31), and then optimally merge these satellite estimates
to produce 3-hourly precipitation fields. Algorithm 3B-43 merges monthly
averaged 3B-42 estimates with gauge data over land to produce the
best-estimated monthly precipitation field. The data sets cover the period
January 1998--present (with about a month delay). Both 3B-42 and 3B-43 products
are observation-only datasets, that is, a gridded analysis based on
satellite-only estimate of rainfall, and a combined satellite/rain gauge
estimate of rainfall, respectively. There are two fields in each data set -
estimates of surface precipitation and RMS random error.
The data set archive consists of binary data
sets in Hierarchical Data Format (HDF). Each 3B-42 file contains a 3-hourly
estimate and each 3B-43 file contains a one month estimate.
First point center = (49.875S,179.875W)
Second point center = (49.625S,179.625W)
Last point center
= (49.875N,179.875E)
Missing values are denoted by the value -9999.9,
and the units are mm/hour.
Technical documentation is available though
the more information hot link at the bottom of the page, and the standard
reference is:
Huffman, G.J., R.F. Adler, D.T. Bolvin, G. Gu, E.J. Nelkin, K.P. Bowman,
E.F. Stocker, D.B. Wolff, 2007: The TRMM Multi-satellite Precipitation
Analysis: Quasi-Global, Multi-Year, Combined-Sensor Precipitation
Estimates at Fine Scale. J. Hydrometeor., 8, 33-55.
The dataset creator is:
David T. Bolvin
Code 613.1
NASA Goddard Space Flight Center
Greenbelt, MD 20771 USA
Phone: +1 301-614-6323
Fax: +1 301-614-5492
Internet: david.t.bolvin@nasa.gov