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ON-DEMAND PROCESSING
How do I order
processing of L1A data to L1B?
LP DAAC Announces New ASTER Level-1B On-Demand Data Sets
Starting on May 24, 2006, LP DAAC began offering all ASTER Level-1 data sets
as on-demand products. Two reasons are responsible for this change:
- This action allows the LP DAAC to offer the entire ASTER Level-1A archive
for Level-1B processing. Previously, we were constrained by which Level-1A
data sets were available as Level-1B data sets. This now provides users the
opportunity to request a Level-1B from any existing Level-1A data set,
effectively quadrupling the number of L1B scenes.
- This action further enables the LP DAAC to produce an updated ASTER
Level-1 product incorporating the most up-to-date corrections and algorithm
changes to ASTER's geometry and radiometry implemented by the Ground Data
System (GDS) in Tokyo, Japan.
The corrected and updated ASTER Level-1A data are used to generate the
Level-1B data set, which in turn is used as the input for generating all the
higher-level products (except the ASTER DEM, which uses an ASTER Level-1A data
set).
Users may choose to order the new Level-1A, Level-1B, or any of the
higher-level products. All the Level-1 data sets and higher-level products are
distributed via the FTP-Pull process or on DVD discs. The Level-1B data sets are offered with standard projection
and resampling options.
For more information, please visit
http://lpdaac.usgs.gov/news/news_aster_051506.asp.
How do I order higher
level data products?
In the new all on-demand system, the ASTER archive consists of only Level 1A
data. A user can order ANY product be created from ANY L1A scene. This includes
a L1A product and L1B product. All higher level products are
created on-demand from L1A data. The most common way to
order Level 1A, 1B, 2 and 3 products is to do a search for data using the
EOS Data Gateway (EDG),
then follow the link to specify and order all products. This will take
you to a menu where you can choose which product you want, and allows you to
change the processing parameters. A parallel search and order
system for higher level products is operated by the Japanese ASTER Ground
Data System . Prior to submitting a DPR
(Data Processing Request) you will need to register with GDS--use the User
Registration link from the
GDS
Main Menu.
On Demand Processing
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