Earth Observation Research Center (EORC), Japan Aerospace Exploration Agency (JAXA)
updated August 2010
GSMaP Data Format Description
This document describes data format of GSMaP Standard (post-processing, 1998-2006) version products, which
was developed based on activities of the GSMaP (Global Satellite Mapping of Precipitation) project. The
GSMaP project was sponsored by Core Research for Evolutional Science and Technology (CREST) of
the Japan Science and Technology Agency (JST) during 2002-2007. Since 2007, GSMaP project
activities are promoted by the JAXA Precipitation Measuring Mission (PMM) Science Team.
Please see the following website for the GSMaP Standard (post-processing, 1998-2006) version products;
http://sharaku.eorc.jaxa.jp/GSMaP_crest/
Data Format
•
All binary files are produced in little-endian byte order platform, and archived with compressed using
“gzip”.
•
Missing values are -999.9 (no observation) and -1.0 (observed, but missing due to low temperature, sea ice
and etc.).
•
•
Units of the all dataset are mm/hr.
Time definition
 A hourly data means averages from XX:00Z to XX:59Z of the specified day, and its file name is
entitled as ‘XX’.
 A daily data means averages from 00:00Z to 23:59Z of the specified day.

•
A monthly data means averages from 1st 00:00Z to the end day 23:59Z of the specified month.
We have two kinds of horizontal resolutions.
○ 0.1 x 0.1 lat/lon degree grid
Products: GSMaP_MVK+, GSMaP_MVK
Grid of those files consists of 3600 x 1200 pixels, which are longitude-latitude elements corresponding to a
0.1 x 0.1 degree grid that covers the global region from 60N to 60S. The center longitude and latitude of the
first pixel [1,1] (left top corner) is [0.05E, 59.95N] (Figure 1).
○ 0.25 x 0.25 lat/lon degree grid
Products: the others
Grid of those files consists of 1440 x 480 pixels, which are longitude-latitude elements corresponding to a
0.25 x 0.25 degree grid that covers the global region from 60N to 60S. The center longitude and latitude of the
first pixel [1,1] (left top corner) is [0.125E, 59.875N] (Figure 2).
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Earth Observation Research Center (EORC), Japan Aerospace Exploration Agency (JAXA)
The first pixel is on left-top corner [1,1]:
(0.05E, 59.95N)
3600 pixels
1200 pixels
The last pixel is on right-bottom corner [3600:1200]:
(0.05W, 59.95S)
Figure 1
Data Coverage Map for 0.1 x 0.1 deg. lat/lon
The first pixel is on left-top corner [1,1]:
(0.125E, 59.875N)
1440 pixels
480 pixels
The last pixel is on right-bottom corner [1440:480]:
(0.125W, 59.875S)
Figure 2
Data Coverage Map for 0.25 x 0.25 deg. lat/lon
Algorithm inputs
1) Geostationary satellite data
Globally-merged pixel-resolution data of MTSAT, METSOSAT-7/-8, GOES-11/-12 provided by
NOAA/CPC. The range of the latitude is 60N-60S. The temporal resolution is 1 hour in this
product.
2) Low Earth Orbit satellite data
Satellite
TRMM
Height (km)
402
MWR
TMI
2
frequency (GHz)
10,19,21,37,85
Earth Observation Research Center (EORC), Japan Aerospace Exploration Agency (JAXA)
AQUA
DMSP-F11
DMSP-F13
DMSP-F14
DMSP-F15
705
803
803
803
803
AMSR-E
SSM/I
SSM/I
SSM/I
SSM/I
7,10,19,24,37,89
19,37,85
19,37,85
19,37,85
19,37,85
3) Ancillary Data
• JMA Global Analysis (GANAL)
• JMA Merged satellite and in situ data Global Daily Sea Surface Temperatures (MGDSST)
Some caveats for data users
• Although JAXA/EORC has taken every care to manage the current site, JAXA assumes no
responsibility regarding the safety of the contents of the Site or the reliability of information
provided on the Site. JAXA is not responsible to you for any damage that may be caused by
the use of the Site and/or the information on the Site.
• Please contact the TRMM Realtime office (
) in advance if you want to
distribute images or data from this site to many people, such as in a pamphlet or internet.
Also, please check JAXA Site Policy for details (http://www.jaxa.jp/policy_e.html).
• Anyone wishing to publish any results using the data from the GSMaP should clearly
acknowledge the ownership of the data in the publication. For example, 'The GSMaP Project
was sponsored by JST-CREST and is promoted by the JAXA Precipitation Measuring
Mission (PMM) Science Team, and the GSMaP products were distributed by the Earth
Observation Research Center, Japan Aerospace Exploration Agency.’ If you have benefited
from GSMaP rainfall products, please cite the major papers listed in references.
• We would appreciate receiving a preprint and/or reprint of publications in which you utilize
our data. Relevant publications should be sent to:
TRMM Real-Time Office
Earth Observation Research Center, Japan Aerospace Exploration Agency
2-1-1, Sengen, Tsukuba-city, Ibaraki 305-8505 Japan
Fax +81-29-868-2961
E-mail:
• Please contact us at the TRMM Realtime office (
) if you have any
questions.
References
Papers describing the GSMaP project and algorithm are as follows.
K. Okamoto, T. Iguchi, N. Takahashi, K. Iwanami and T. Ushio, 2005: The global satellite mapping of
precipitation (GSMaP) project. 25th IGARSS Proceedings, 3414-3416.
T. Kubota, S. Shige, H. Hashizume, K. Aonashi, N. Takahashi, S. Seto, M. Hirose, Y. N. Takayabu, K.
Nakagawa, K. Iwanami, T. Ushio, M. Kachi, and K. Okamoto, 2007: Global Precipitation Map using
Satelliteborne Microwave Radiometers by the GSMaP Project : Production and Validation. IEEE Trans.
Geosci. Remote Sens., 45(7), 2259-2275.
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Earth Observation Research Center (EORC), Japan Aerospace Exploration Agency (JAXA)
K. Aonashi, J. Awaka, M. Hirose, T. Kozu, T. Kubota, G. Liu, S. Shige, S., Kida, S. Seto, N. Takahashi, and Y.
N. Takayabu, 2009: GSMaP passive, microwave precipitation retrieval algorithm: Algorithm description
and validation. J. Meteor. Soc. Japan, 87A, 119-136.
T. Ushio, T. Kubota, S. Shige, K. Okamoto, K. Aonashi, T. Inoue, N., Takahashi, T. Iguchi, M. Kachi, R. Oki,
T. Morimoto, and Z. Kawasaki, 2009: A Kalman filter approach to the Global Satellite Mapping of
Precipitation (GSMaP) from combined passive microwave and infrared radiometric data. J. Meteor. Soc.
Japan, 87A, 137-151.
Contact
TRMM Real-Time Office
Earth Observation Research Center (EORC), Japan Aerospace Exploration Agency (JAXA)
2-1-1, Sengen, Tsukuba-city, Ibaraki 305-8505 Japan
Fax +81-29-868-2961
E-mail:
) if you have any questions.
Please contact us at the TRMM Realtime office (
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