JAXA/EOC announces that the distribution of some of the AMSR-E (Advanced Microwave Scanning Radiometer for EOS on Aqua satellite) products has resumed from Dec. 21st, 2004(JST). Since Nov 4th, 2004, some of AMSR-E products have been suspended the data production and distribution due to the data deficit of the AMSR-E 89GHz receiver A. However, this is made possible by the completion of modifications to the processing software to accommodate the data deficit of AMSR-E 89GHz receiver A.

1. Resumption of AMSR-E products and the effects on the products by algorithm improvement.


We have modified the production codes of Level-2 precipitation and snow products to accommodate the data deficit of the AMSR-E. The effects of this change are as follows.


• Level-2 Products (AP: Amount of Precipitation, SWE: Snow Water Equivalence)

Swath coverage of 89A and 89B are slightly different. The 89B observes about 15km behind the 89A and the swath width of 89B is narrower about 30km than that of 89A at both edges of the swath. Therefore, in case only the 89B Tb are available, there are some missing pixels about one point at both swath edges and one line at the end of file in the Level 2 precipitation and snow products. This corresponds to less than 1% of the total number of pixels.
Regarding the precipitation product (AP), we confirmed that the retrieved rain rates were underestimated about 1-2% compared to the previous product due to the averaging effects of 89GHz Tb. JAXA believes that the practical impact of this change is small.
Regarding the snow product (SWE), there are no changes of snow depth values since the 89GHz Tb are not used in estimating the snow parameters.


• Level-3 Products (AP: Amount of Precipitation, SWE: Snow Water Equivalence)

Due to the missing areas of Level-2 products, number of samples in certain grids will be decreased. However, average values of geophysical parameter will not be affected so much. Changes of rain rates are the same as observed in Level 2 product.



Please refer to the following URL for more details information
URL : http://sharaku.eorc.jaxa.jp/AMSR/data_re/amsre/89GHzA.html

The following services simultaneously also be resumed.
• Catalog Search for Level-2 and Level-3 products (AP, SWE)
• Product Order for Level-2 and Level-3 products (AP, SWE)



2. Reprocessing schedule for suspended products:

The observed data from Nov. 1st to Dec. 20th, 2004 are being re-processed with the updated algorithm software and will be available according to the progress of re-processing. JAXA will require about five days to re-process it.

(Note): we plan re-processing of all mission data since Jun. 1st, 2002 using the same algorithm at the time of the next version-up (scheduled at the end of Feb. 2005)



3. The status of the products available with some quality degradation:

The phenomenon of the data deficit of AMSR-E is still under investigation by JAXA. Therefore, in level-1 product, the data deficit of the AMSR-E is continuing.

Level-1A:	Data deficit in 89GHz A receiver
Level-1B:	Data deficit in 89GHz A receiver
Level-3 Brightness Temperature:	Decreased samples in the grid of 89GHz data

Contact Point:	Order desk, Earth Observation Center, JAXA
TEL:	+81-49-298-1307
FAX:	+81-49-298-1389
E-mail:	orderdesk@eoc.jaxa.jp

JAXA sincerely apologizes for any inconvenience and deeply appreciates for your understanding and cooperation. We hope you will continue to utilize earth observation data.