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AMSR AMSR-E
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AMSR2 AMSR2

Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and




GCOM-W (AMSR2) Rainfall Products

Sensor Description:

AMSR-E/AMSR2 is a concically scanning passive microwave radiometer sensing microwave radiation at 12 channels and 6 frequencies ranging from 6.9 to 89 GHz. The AMSR-E instrument is on board the EOS Aqua platform and has been operating since June of 2002. The AMSR2 instrument is on board the GCOM-W platform and has been operating since July of 2012.

Algorithm Description:

GPROF 2008: The rainfall algorithm used to compute rainfall estimates from the AMSR-E/AMSR2 brightness temperature data is the 2008 release of the Goddard PROFiling algorithm (GPROF) [Kummerow et al., 2001, Masunaga and Kummerow, 2005]. The AMSR-E version of GPROF is run operationally and level 2 (i.e. instantaneous pixel resolution) rainfall estimates are distributed by the National Snow and Ice Data Center (NSIDC). Additional information is available on the AMSR-E implementation details.

Version Information:
  • GPR08.B3 (GPROF 2008 beta version 3): Initial version implemented for AMSR-E.
  • GPR08.B4 (GPROF 2008 beta version 4): A number of changes were made to the level 2 output including the addition of a data quality flag. There are significant changes in the output data fields particularly with respect to rainfall estimates over land and coast.
  • GPR08.B5 (GPROF 2008 beta version 5): Minor changes were made to the level 2 output, but no significant changes were made to the daily and monthly gridded output products. As a result, the gridded products on this site were not updated to B5.
  • GPR08.B6 (GPROF 2008 beta version 6): B6 is a beta version 6. Changes to the level 2 output include a number of bug fixes along with the following improvements/changes. These include an improvement to the sea-ice edge detection algorithm, the use of higher resolution (0.25x0.25 degree) daily Reynolds SST data, and changes to the channel weights based on individual channel errors. To improve the consistency between rainfall estimates from different sensors a modification was made to the rain screening methodology used in the optimal estimation procedure for retrieving geophysical paramters over non-raining scenes. Finally, for sensors other than TMI several adjustments were made to the apriori databases to improve the consistency in the output rainfall estimates.
  • GPR10.V1 (GPROF 2010 version 1): The apriori database was finalized based on the TRMM version 7 products. Note that the land algorithm has not been updated at this time and thus the land retrievals are set to missing.
  • GPR10.V2 (GPROF 2010 version 2): A number of updates were made to the V1 retrieval to improve consistency between sensor and screen for desert on snow-covered regions over land. The land retrievals have been updated and are now available for all the sensors.

Input Brightness Temperature Data:

The rainfall products provided here are computed from the Level 1C brightness temperature dataset.

Data Availability:

The EOS Aqua satellite carrying AMSR-E is in a polar orbit providing near global coverage. It was launched on May 4, 2002 and rainfall estimates from AMSR-E are available starting June 1, 2002 and continuing to the present.

Rainfall Data:

FTP Daily and Monthly Gridded Rainfall Data Files
File Format Specification for Daily Gridded Rainfall Files
File Format Specification for Monthly Gridded Rainfall Files

Rainfall Images:

Create/Display Daily Rainfall Images
Create/Display Monthly Rainfall Images
FTP Pre-rendered Rainfall Images

Software:

Get software to read the binary gridded rainfall files.

Additional Documentation/References:

–   Wilheit, T., C. Kummerow and R. Ferraro, 2003: Rainfall algorithms for AMSR-E, IEEE Trans. Geoscience and Rem. Sensing, 41, 204-214.
–   Kummerow, C., Y. Hong, W. S. Olson, S. Yang, R. F. Adler, J. McCollum, R. Ferraro, G. Petty, D. B. Shin, and T. T. Wilheit, 2001: The evolution of the Goddard profiling algorithm (GPROF) for rainfall estimation from passive microwave sensors, J. Appl. Meteor., 40, 1801-1820.
–   Masunaga, H. and C. D. Kummerow, 2005: Combined radar and radiometer analysis of precipitation profiles for a parametric retrieval algorithm, J. Atmos. Oceanic Technol., 22, 909-929.

Related Links:

National Snow and Ice Data Center (NSIDC)
NASA Marshall Space Flight Center
JAXA Earth Observation Research Center (EORC)